Progress in the field of portable plasmon biosensors by Zhang Weihua and Lu Zhenda of Nanjing University

Today, the rapid development and popularization of smart phones has become an indispensable part of people's daily life At the same time, as a portable tool integrating communication, computing, optical imaging and other functions, smart phones also provide the possibility to realize all kinds of portable health detection devices and provide fast, convenient and high-quality health services for families or remote areas In order to achieve this goal, researchers put forward many schemes, trying to combine micro nano biochemical sensor based on optics, especially plasmon sensor and mobile phone However, because the high-precision reading of the data of the traditional plasmon sensor depends on the measurement of spectrum or angle spectrum, a more complex reading device is needed, which limits the miniaturization of the final device In order to break the above limitation, Professor Zhang Weihua's research group and Professor Lu Zhenda's research group of College of modern engineering and Applied Sciences of Nanjing University have developed a kind of patterned plasmonic gradient (PPG) The sensor can convert the local refractive index information into two-dimensional image information, i.e the size of the resonance ring, so that the data can be read out directly using the photo taking function of the smartphone The experimental results show that the refractive index measurement accuracy of PPG sensor is better than < 0.001 RIU, and the adsorption process of trace (20 μ L, ~ 10 nm) protein can be detected in real time (detection limit is ~ 1 nm) (Fig 1) The related results were published in nanoscale (DOI: 10.1039 / c9nr00455f) under the title of "patterned plasma gradient for high precision biosensoring using smartphone reader" At the same time, the design of the PPG sensor has been granted a patent (201710149279.3) Dr Bian Jie is the first author of the paper, and Prof Zhang Weihua and Prof Lu Zhenda are the corresponding authors The research was supported by the nano project of the Ministry of science and technology, the innovation group of NSFC, and the general program of NSFC Fig 1 (a) the relationship between the size of the resonance ring and the reciprocal of the refractive index of the gradient pattern plasmon sensor (b) the specific adsorption experiment of trace protein molecular samples (20 μ L, ~ 10 nm) (source: Nanjing University)