• Analysis of the mechanical properties of chromosomes in air and liquid by AFM

      Wang, Bowei; Yang, Fan; Dong, Jianjun; Li, Jiani; Wang, Ying; Qu, Kaige; Wei, Huimiao; Wang, Zuobin; Changchun University of Science and Technology; Changli Nano Biotechnology Ltd; et al. (IEEE, 2021-11-18)
      Chromosomes contain all the genomic information thus making the study of chromosomes practical and significant. Herein, the morphologies of chromosomes prepared with different methods were monitored by atomic force microscopy (AFM). Moreover, the mechanical properties of chromosomes in air and liquid were investigated quantitatively through AFM-based force spectroscopy. The differences of chromosome morphologies and mechanical properties caused by sample preparations indicated that the chromosome characterization in liquid was more meaningful to reveal the physiological characteristics of chromosomes.
    • Antireflection silicon structures with hydrophobic property fabricated by three-beam laser interference

      Zhao, Le; Wang, Zuobin; Zhang, J.; Cao, L.; Li, L.; Yue, Y.; Li, Dayou; Changchun University of Science and Technology; University of Bedfordshire; Jiaotong-Liverpool University (Elsevier, 2015-08-15)
      This paper demonstrates antireflective structures on silicon wafer surfaces with hydrophobic property fabricated by three-beam laser interference. In this work, a three-beam laser interference system was set up to generate periodic micro-nano hole structures with hexagonal distributions. Compared with the existing technologies, the array of hexagonally-distributed hole structures fabricated by three-beam laser interference reveals a design guideline to achieve considerably low solar-weighted reflectance (SWR) in the wavelength range of 300-780 nm. The resulting periodic hexagonally-distributed hole structures have shown extremely low SWR (1.86%) and relatively large contact angle (140°) providing with a self-cleaning capability on the solar cell surface.
    • Capture and sorting of multiple cells by polarization-controlled three-beam interference

      Hou, Yu; Wang, Zuobin; Hu, Yaowei; Li, Dayou; Qiu, Renxi; Changchun University of Science and Technology; University of Bedfordshire (IOP PUBLISHING LTD, 2016-02-02)
      For the capture and sorting of multiple cells, a sensitive and highly efficient polarization-controlled three-beam interference set-up has been developed. With the theory of superposition of three beams, simulations on the influence of polarization angle upon the intensity distribution and the laser gradient force change with different polarization angles have been carried out. By controlling the polarization angle of the beams, various intensity distributions and different sizes of dots are obtained. We have experimentally observed multiple optical tweezers and the sorting of cells with different polarization angles, which are in accordance with the theoretical analysis. The experimental results have shown that the polarization angle affects the shapes and feature sizes of the interference patterns and the trapping force.
    • Cellular shear adhesion force measurement and simultaneous imaging by atomic force microscope

      Hou, Yu; Wang, Zuobin; Li, Dayou; Qiu, Renxi; Li, Yan; Jiang, Jinlan; Changchun University of Science and Technology; Chinses Academy of Sciences; University of Bedfordshire; Jilin University (Springer, 2017-01-06)
      This paper presents a sensitive and fast cellular shear adhesion force measurement method using an atomic force microscope (AFM). In the work, the AFM was used both as a tool for the imaging of cells on the nano-scale and as a force sensor for the measurement of the shear adhesion force between the cell and the substrate. After the cell imaging, the measurement of cellular shear adhesion forces was made based on the different positions of the cell on the nano-scale. Moreover, different pushing speeds of probe and various locations of cells were used in experiments to study their influences. In this study, the measurement of the cell adhesion in the upper portion of the cell is different from that in the lower portion. It may reveal that the cancer cells have the metastasis tendency after cultured for 16 to 20 hours, which is significant for preventing metastasis in the patients diagnosed with early cancer lesions. Furthermore, the cellular shear adhesion forces of two types of living cancer cells were obtained based on the measurements of AFM cantilever deflections in the torsional and vertical directions. The results demonstrate that the shear adhesion force of cancer cells is twice as much as the same type of cancer cells with TRAIL. The method can also provide a way for the measurement of the cellular shear adhesion force between the cell and the substrate, and for the simultaneous exploration of cells using the AFM imaging and manipulation
    • Determination of beam incidence conditions based on the analysis of laser interference patterns

      Wang, Dapeng; Wang, Zuobin; Yue, Yong; Yu, Juncai; Tan, Chunlei; Li, Dayou; Qiu, Renxi; Maple, Carsten; Changchun University of Science and Technology; University of Bedfordshire; et al. (Elsevier GmbH, 2015-07-17)
      Beam incidence conditions in the formation of two-, three- and four-beam laser interference patterns are presented and studied in this paper. In a laser interference lithography (LIL) process, it is of importance to determine and control beam incidence conditions based on the analysis of laser interference patterns for system calibration as any slight change of incident angles or intensities of beams will introduce significant variations of periods and contrasts of interference patterns. In this work, interference patterns were captured by a He-Ne laser interference system under different incidence conditions, the pattern period measurement was achieved by cross-correlation with, and the pattern contrast was calculated by image processing. Subsequently, the incident angles and intensities of beams were determined based on the analysis of spatial distributions of interfering beams. As a consequence, the relationship between the beam incidence conditions and interference patterns is revealed. The proposed method is useful for the calibration of LIL processes and for reverse engineering applications.
    • A dynamic feedback algorithm of AFM based on cell morphology changes

      Cheng, Can; Wang, Xinyue; Dong, Jianjun; Liu, Zimin; Wang, Zuobin; Changchun University of Science and Technology; University of Bedfordshire (IEEE, 2021-11-18)
      The atomic force microscope (AFM) used in biological research as a powerful tool has been for many years. However, the imaging of living cells is still a problem as the sample is too high and too soft to obtain their accurate morphologies. Especially in the high-speed scanning mode, AFM does not have enough judgments to make accurate measurements at the down part of the sample. In this study, we propose an improved control method to improve the image quality of living human colon cancer cells (SW480) especially in the down part during the scanning.
    • Effect of astragalus polysaccharides on cancer cells studied by AFM

      Lu, Zhengcheng; Wang, Zuobin; Li, Dayou; Zhu, Wenyu; Wang, Rui; Qu, Kaige; Yan, Jin; University of Bedfordshire; Changchun University of Science and Technology (IEEE, 2021-11-18)
      As a traditional Chinese medicine, astragalus and its products are used in cancer treatment aiming to reduce the side effects of chemotherapy. Cells are the most basic unit of living organisms, and AFM directly obtains information from living cells on the micro/nano scale. Therefore, the use of AFM to study the interaction between astragalus and cells is conducive to a full range of drug efficacy evaluation and provides a new way for drug development. In this paper, astragalus polysaccharides were extracted from astragalus, which were diluted into solutions of different concentrations. Combined with the MTT experiment, the effects of Astragalus polysaccharide on cancer cells and benign cells were studied by AFM.
    • Effect of different trypsin concentrations on SMCC-7721 cell adhesion

      Yan, Jin; Tian, Liguo; Xie, Chenchen; Liu, Yan; Lu, Zhengcheng; Wang, Zuobin; Changchun University of Science and Technology; University of Bedfordshire (International Journal of Pharma Medicine and Biological Sciences, 2021-07-03)
      In this work, living human liver cancer cells (SMCC-7721) were exposed to the trypsin solution at the concentrations of 1.5 mg/ml, 2.0 mg/ml, 2.5 mg/ml, 3.0 mg/ml, 3.5 mg/ml and 4.0 mg/ml, respectively. After 2 min of dosing time, the physical and mechanical properties of the cells were detected by Atomic Force Microscope (AFM). With the increase of the trypsin concentration, the adhesion force between the cell and the probe gently decreased. The maximum lateral deflection voltage variation of the probe, which reflected the maximum external force that kept the cells attached to the substrate, was significantly reduced. This work indicates that we may change the cell morphology and regulate the mechanical properties of cells by controlling the concentration of trypsin solution to treat cells, which has important implications for bioengineering and cell manipulation.
    • Effect of SMMC-7721-derived exosomes on hepatocytes studied by AFM

      Ju, Tuoyu; Yang, Fan; Wang, Ying; Song, Zhengxun; Xu, Hongmei; Chen, Yujuan; Wang, Zuobin; Changchun University of Science and Technology; University of Bedfordshire (IEEE, 2021-11-18)
      Exosomes play an important role in the early diagnosis and development of hepatocellular carcinoma (HCC). In the past, researchers mainly studied the contents of exosomes and the biological mechanism on cells, but the changes of mechanical properties of cells caused by exosomes are not clear. In this study, the changes of mechanical properties of hepatocytes (L-02) co-cultured with exosomes (7721-exos) derived from HCC (SMMC-7721) with low metastatic ability were studied. The 7721-exos were able to promote the proliferation and rearrange the cytoskeleton of L-02 cells. The atomic force microscopy measurement results showed that the height was increased, the adhesion and the elastic modulus were reduced. The effect was concentration dependent. The changes of cell mechanical properties induced by exosomes were of great significance for further studying the mechanism of exosomes.
    • Effects of laser fluence on silicon modification by four-beam laser interference

      Zhao, Le; Wang, Zuobin; Zhang, Jinjin; Yu, Miao; Li, Siwei; Li, Dayou; Yue, Yong; Changchun University of Science and Technology; University of Bedfordshire; Jiaotong-Liverpool University (American Institute of Physics Inc., 2015-12-17)
      This paper discusses the effects of laser fluence on silicon modification by four-beam laser interference. In this work, four-beam laser interference was used to pattern single crystal silicon wafers for the fabrication of surface structures, and the number of laser pulses was applied to the process in air. By controlling the parameters of laser irradiation, different shapes of silicon structures were fabricated. The results were obtained with the single laser fluence of 354 mJ/cm, 495 mJ/cm, and 637 mJ/cm, the pulse repetition rate of 10 Hz, the laser exposure pulses of 30, 100, and 300, the laser wavelength of 1064 nm, and the pulse duration of 7-9 ns. The effects of the heat transfer and the radiation of laser interference plasma on silicon wafer surfaces were investigated. The equations of heat flow and radiation effects of laser plasma of interfering patterns in a four-beam laser interference distribution were proposed to describe their impacts on silicon wafer surfaces. The experimental results have shown that the laser fluence has to be properly selected for the fabrication of well-defined surface structures in a four-beam laser interference process. Laser interference patterns can directly fabricate different shape structures for their corresponding applications.
    • Electrical conductivity measurement of λ DNA molecules by conductive atomic force microscopy

      Wang, Ying; Xie, Ying; Gao, Mingyan; Zhang, Wenxiao; Liu, Lanjiao; Qu, Yingmin; Wang, Jiajia; Hu, Cuihua; Song, Zhengxun; Wang, Zuobin; et al. (IOP Publishing, 2021-11-08)
      Conductive atomic force microscopy (C-AFM) is a powerful tool used in the microelectronics analysis by applying a certain bias voltage between the conducting probe and the sample and obtaining the electrical information of sample. In this work, the surface morphological information and current images of the lambda DNA (λ DNA) molecules with different distributions were obtained by C-AFM. The 1 and 10 ng μl−1 DNA solutions were dripped onto mica sheets for making randomly distributed DNA and DNA network samples, and another 1 ng μl−1 DNA sample was placed in a DC electric field with a voltage of 2 V before being dried for stretching the DNA sample. The results show that the current flowing through DNA networks was significantly higher than the stretched and random distribution of DNA in the experiment. The I–V curve of DNA networks was obtained by changing the bias voltage of C-AFM from −9 to 9 V. The currents flowing through stretched DNA at different pH values were studied. When the pH was 7, the current was the smallest, and the current was gradually increased as the solution became acidic or alkaline.
    • Fabrication of hierarchical Ti6Al4V structures by hydrothermal treatment and laser interference lithography with enhanced ice resistance

      Liu, Ri; Wu, Xiaoming; Cao, Liang; Liu, Dongdong; Sun, Baishun; Weng, Zhankun; Wang, Zuobin; Changchun University of Science and Technology; University of Bedfordshire (IEEE, 2021-11-18)
      Icing widely exists in aerospace, transportation and electric power communication, causing great safety risks to people's production and life. Inhibiting icing is of great significance in practical engineering applications, and thus, employing an economical and efficient anti-icing method is a research hotspot. In this work, an anti-icing structured surface was fabricated by combining direct laser interference lithography (DLIL) with hydrothermal treatment. A micro-pillar array structure on the tc4 substrate was easily fabricated by DLIL, and a layer of nano-grass structure on the micro-pillar array was grown by hydrothermal treatment. These hierarchically textured surfaces exhibited low-temperature-adaptive water repellency (150° at −10°C, which delayed the frozen time (DT∼1h) and dropped frozen temperature. The above conditions were analyzed from the angle of wettability and heat conduction, and the influence of structure and wettability on ice resistance was discussed.
    • Fabrication of periodically micropatterned magnetite nanoparticles by laser-interference-controlled electrodeposition

      Wang, Lu; Dong, Litong; Li, Li; Weng, Zhankun; Xu, Hongmei; Yu, Miao; Wang, Zuobin; Changchun University of Science and Technology (Springer US, 2017-11-09)
      This paper introduces a laser-interference-controlled electrochemical deposition method for direct fabrication of periodically micropatterned magnetite (Fe3O4) nanoparticles (NPs). In this work, Fe3O4 NPs were controllably synthesized on the areas where the photoconductive electrode was exposed to the periodically patterned interferometric laser irradiation during the electrodeposition. Thus, the micropattern of Fe3O4 NPs was controlled by interferometric laser pattern, and the crystallization of the particles was controlled by laser interference intensity and electrochemical deposition conditions. The bottom-up electrochemical approach was combined with a top-down laser interference methodology. This maskless method allows for in situ fabrication of periodically patterned magnetite NPs on the microscale by electrodeposition under room temperature and atmospheric pressure conditions. In the experiment, Fe3O4 NPs with the mean grain size below 100 nm in the pattern of 5-lm line array were achieved within the deposition time of 100 s. The experiment results have shown that the proposed method is a one-step approach in fabricating large areas of periodically micropatterned magnetite NPs.
    • Growth behavior of SHSY5Y cells on hybrid micro-pit and nano-pillar arrays

      Wu, Xiaomin; Li, Li; Liu, Ri; Weng, Zhankun; Wang, Zuobin; Changchun University of Science and Technology; University of Bedfordshire (IEEE, 2021-11-18)
      The directional arrangement and extension of cells is of great significance in the tissue engineering field. Great efforts have been made to study the effects of micro- or nano- structures on cell behaviors, but they are still poorly understood. In this work, hybrid micro/nano structures prepared by combining laser marking technology with metal assisted chemical etching (MACE) were introduced to study their effect on the growth behavior of SHSY5Y cells. It was found that the cells on the silicon micro-pit arrays (SiMP arrays, unetched substrate) were arranged orderly along the edge of the micro-pits, stretched and connected with each other, while the cells on the hybrid silicon micro-pit and silicon nano-pillar arrays (hybrid SiMP/SiNP arrays, etched substrates) were also arranged in an orderly manner with a relatively short cell stretch, but displayed a preference for independent growth. In addition, about 90% of cells showed a preference for growing on the area of nano-pillars (NPs), and only 10% of cells on the area of micro-pits (MPs) on the etched substrate. The results showed that the hybrid SiMP/SiNP arrays trapped cells and restricted the cell spreading. Thus, this approach is of great significance for the study of independent growth behavior of cells on the substrate in the field of single neuron research.
    • Laser interference field induced re-distribution of Ag nanoparticle arrays

      Yue, Ming; Liu, Mengnan; Li, Li; Liang, Xiubo; Wang, Lu; Wang, Zuobin; Changchun University of Science and Technology; University of Bedfordshire (IEEE, 2021-11-18)
      The wide application of metal nanoparticle arrays has attracted much attention in the field of nanotechnology. Such as quantum dots, structural colors, sensors, metamaterials. In this work, we fabricated periodic micro-and nanostructures through the interference of two beams with the same frequency and vibration direction. By controlling the spot energy and light field energy distribution of Gaussian interference lithography, the various surface characteristics of Ag-Si material system (Ag@Si) are optimized, and the mass transfer brought by Oswald ripening is used to control the Rayleigh instability in the thermal dewetting process. To achieve the purpose of the periodic gradient Ag nanoparticle arrays (AgNPs) pattern can be controlled. The experimental results show that the periodic micro-and nanostructures can be obtained by optimizing the spot energy and the number of pulses.
    • Multi-parameter AFM characterization of INS-1 cells

      Yang, Fan; Wang, Bowei; Wang, Jiajia; Chen, Yujuan; Wang, Zuobin; Changchun University of Science and Technology; University of Bedfordshire (IEEE, 2021-11-18)
      AFM-based single cell force spectroscopy has been employed wildly, while more work is needed for the mechanical detection of diabetes-related cells (INS-1 cells). In this study, a multi-parameter AFM characterization was performed to detect the mechanical properties of INS-1 cells in situ. High resolution topographies and concurrent mechanics were obtained by taking the advantage of the quantitatively imaging (QI) mode AFM. The analyses of force curves and force maps jointly presented the multiple parameters involved in the cell mechanics. The AFM force spectroscopy measurement provides full analysis and comprehensive understanding of cell mechanics.
    • Self-assembly of DNA molecules in magnetic fields

      Gao, Mingyan; Hu, Jing; Wang, Jianfei; Liu, Mengnan; Zhu, Xiaona; Saeed, Sadaf; Hu, Cuihua; Song, Zhengxun; Xu, Hongmei; Wang, Zuobin; et al. (IOP Publishing, 2021-11-18)
      In this work, a rich variety of self-assembled DNA patterns were obtained in the magnetic field. Herein, atomic force microscopy (AFM) was utilized to investigate the effects of the concentration of DNA solution, intensity and direction of magnetic field and modification of mica surface by different cations on the self-assembly of DNA molecules. It was found that owning to the change of the DNA concentration, even under the same magnetic field, the DNA self-assembly results were different. The in situ test results showed that the DNA self-assembly in an magnetic field was more likely to occur in liquid phase than in gas phase. In addition, whether in a horizontal or vertical magnetic field, a single stretched dsDNA was obtained in a certain DNA concentration and magnetic field intensity. Besides, the modification of cations on the mica surface significantly increased the force between the DNA molecules and mica surface, and further changed the self-assembly of DNA molecules under the action of magnetic field.
    • Study on the conductivity of DNA molecules under magnetic fields

      Gao, Mingyan; Hu, Jing; Wang, Jianfei; Liu, Mengnan; Zhu, Xiaona; Tian, Liguo; Hu, Cuihua; Song, Zhengxun; Xu, Hongmei; Wang, Zuobin; et al. (IEEE, 2021-11-18)
      In this work, the conductivity of DNA molecules under the effect of magnetic fields was studied by conductive atomic force microscopy (C-AFM). It is found that the self-assembly images of 7.5 ng/μL DNA aqueous solution on the bare mica and Au layer surfaces are quite different, and the DNA molecules are obviously stretched on the Au layer surface and single stretched DNA strands were obtained. In addition, the conductivity of single stretched DNA molecules in the horizontal stable magnetic field (SMF) and high frequency electromagnetic field (HFEF) were investigated in detail. The results showed that the conductivity of DNA was weakened by the effect of magnetic field.
    • Tapping atomic force microscopy imaging at phase resonance

      Sun, Baishun; Xie, Chenchen; Qu, Kaige; Cao, Liang; Yan, Jin; Wang, Ying; Tian, Liguo; Zhang, Wenxiao; Wang, Zuobin; Changchun University of Science and Technology; et al. (IEEE, 2021-11-18)
      Tapping atomic force microscope (TM-AFM) can measure soft samples, which has the advantages of low loss and high resolution, and has been widely used in the characterization of soft micro-nano materials by atomic force microscope (AFM). The phase image in TM-AFM contains sample properties, and it is an important method to characterize the sample by TM-AFM. At present, researchers usually select the frequency near the first resonance peak of the probe to drive its vibration to carry out scanning imaging. However, the phase sensitivity near the first-order resonance of the probe is not high. Therefore, the phase image of TM-AFM is also less sensitive to characterize micro-nano materials. In order to improve the phase sensitivity of the probe, the probe working at the phase resonance peak was selected in this paper to improve the phase sensitivity of the probe vibration and the imaging quality of TM-AFM phase image. The experimental results show that the phase image of phase resonance-atomic force microscope (PR-AFM) can provide not only the surface information but also the structure information of the sample subsurface. PR-AFM can be applied for better characterization of micro and nano materials.