Research And Implementation Of LSPR Biochemical Sensing Detection System Based On Smartphone

When faced with dilemmas in early diagnosis for cancer patients, LSPR detection technology, with its interface effects, label-free, real-time and non-polluting advantages, has gained widespread attention. Meanwhile, as mobile medical concept rises, including the online medical, home diagnosis, and rapid detection, smartphones can be used as an effective platform for LSPR biochemical sensing. Recently, it is Indian researchers who have firstly introduced the LSPR biochemical sensing system based on smartphones, which collected LSPR detection data via smartphone image sensor. But it was time-consuming with low detection accuracy. This paper proposes a portable LSPR biochemical sensing approach based on smartphones. First, the professional spectrometer is used to obtain high-precision testing data, after which, spectral data is rapidly collected and processed through the smartphone USB interface.This approach, under the premise to ensure the mobile convenience, not only solves the problems above, but also provides a sound platform for Android application. The contributions are as follows:(1) The design and implementation of detection system on hardware platforms.The design of biochemical sensing system on hardware platforms depends on the spectrometer which links the detection system to smartphones. Without modifying the kernel driver of the spectrometer, free USB drive static library is developed for the spectrometer, and the library is compiled into DLL Arm platform via the NDK technology. In this case, smartphones will be able to achieve dynamic library to collect spectral data.(2) The design and implementation of detection system software.In order to design and implement a simple, full-featured and user-friendly Android application, the implementation proceeds according to the software project management process. First, the software needs analysis is conducted for function, interface and performance requirements. Second, through the design of user interface, database and program modules, the purpose of program design can be achieved accordingly. Finally, the software modules are implemented, including user interface, real-time data, local data storage and forwarding four modules. (3) The implementation of spectral data curve fitting algorithm.The spectral data acquired above is stored in the form of two-dimensional coordinate points (wavelength, spectral intensity). When plotting the LSPR biochemical detection curve, a smooth curve is displayed to users. It is found that, compared with the least squares curve and the curve-based RBF, the cubic spline curve fitting algorithm is more suited to processing spectrum of discrete points. In addition, through the fitting function, the extreme points within the specified range can be worked out. These points illustrate the extinction peak wavelength position for the LSPR biochemical detection.(4) LSPR software detection system testing and application research.After the completion of software development, software testing is conducted in detail. With the black box testing, overall tests are implemented for the software interface, interactive features and software performance. It can be found through the tests that the software complies with the application requirements. Meanwhile, LSPR detection system is applied to nanoparticles extinction spectra and viral liver biochemical tests respectively. The system detection demonstrates very high precision.In short, the innovation of this paper is putting forward a complete LSPR biochemical sensing approach based on Android smartphones; also, designing and implementing the hardware and software platforms for the system; and passing a comprehensive software testing. At the same time, the system has been successfully applied to detect LSPR nanoparticles and liver virus, whose test results are in line with expectations.