Recently, the team of Professor Wang Yiping of the School of Physics and Optoelectronics Engineering of Shenzhen University published a paper in the internationally renowned Nano science and technology journal Nano Letters (the first region of the Chinese Academy of Sciences, Nature Index journal, impact factor 10).8) Published a research paper entitled "An Optical Fiber-Based Nanomotion Sensor for Rapid Antibiotic and Antifungal Susceptibility Tests" in the form of a journal cover paper。In this paper, a novel ultra-sensitive nano-vibration sensor based on fiber is reported. By using femtosecond laser two-photon polymerization of 3D printed micro-cantilever beam on the fiber end face, it is used for rapid antibiotic and antibacterial drug sensitivity test, greatly improving the test speed, and realizing the miniaturization and simplification of the test device。Prof. Changrui Liao, Shenzhen University, and Dr. Jiangtao Zhou, Ecole Polytechnique Lausanne, Switzerland are co-first authors, while Prof. Yiping Wang, Changrui Liao, Shenzhen University, and Prof. Sandor Kasas and Dr. Jiangtao Zhou, Ecole Polytechnique Lausanne, Switzerland, are co-corresponding authors。
图1.Schematic diagram of nano-vibration sensor based on optical fiber
In recent years, the abuse of antimicrobial drugs has led to widespread antimicrobial resistance in microorganisms, which has gradually become a global public health problem。An important method to limit its spread is to diagnose resistant bacteria through antimicrobial susceptibility testing. However, the main problems of current sensitivity testing methods are slow testing speed and low degree of parallelization。Compared to traditional drug sensitivity testing that takes tens of hours or even weeks, our ultra-sensitive fibre-based nanovibratory sensor can identify resistant microbes in 1-3 hours, so that the most appropriate drug against a particular organism can be determined。 Compared to the latest ultra-sensitive nano-vibration sensors based on atomic force microscopes, our test speed is close but the degree of miniaturization is high, and the potential for future integrated and parallel testing is very broad。
In this work, we propose a fiber based nano-vibration sensor based on the principle that the Fabry-Perot (FP) interferometer composed of fiber end face and cantilever beam changes their optical path difference when the cantilever beam vibrates in living microorganisms, resulting in dynamic changes in interference。The core of its sensitivity testing is the flexible 3D printing of ultra-sensitive cantilever beams through two-photon polymerization (2PP) technology。We implemented 2PP printing in the vertical direction to achieve a thinner cantilever, with a final thickness of around 1 micron。In addition, the relatively low power of the femtosecond laser and the relatively fast scanning speed during the polymerization process make the inherent stiffness of the polymer structure related to its Young's modulus low, thus increasing the spring constant and detection sensitivity of the cantilever beam。The spring constant of the cantilever beam is as low as about 0.3 N/m, the same order of magnitude as the commercial silicon nitride AFM cantilever。As a proof-of-concept prototype, we demonstrated that this fibre-based nano-vibration sensor showed excellent performance in real-time sensitivity tests of E. coli and Candida albicans to antibiotics and antifungal drugs, respectively, detecting nano - or subnano cantilever vibrations caused by their metabolic activity。This nanovibratory sensor strategy, which combines the advantages of fast response and parallelization, may propel the technology to become the next generation of nanovibratory sensors for large-scale and rapid antimicrobial sensitivity testing and other technical and biomedical applications。
图2. Schematic diagram of laser processing of fibre-based nano-vibration sensor
图3.The nanoscale activity of ampicillin sensitive Escherichia coli was detected by optical fiber nanoscale vibration sensor
The research was supported by the National Science Foundation for Outstanding Youth and the International Science and Technology Cooperation Project of Guangdong Province。
Link to the original paper:http://pubs.acs.org/doi/10.1021/acs.nanolett.3c03781?ref=pdf
(Source School of Physics and Optoelectronic Engineering)
