Multi-Parameter surface plasmon resonance instrument for multiple nucleic acid quantitative detection

In this paper, a low-cost multi-parameter surface plasmon resonance (SPR) instrument is designed for the detection of nucleic acids with a functional biosensor. The photodiode array is used as the photodetector of the sensing system, which is cooperated with the linear light source, prism, and mechanical transmission system to form an integrated opto-mechatronic system. An adaptive threshold correction algorithm is proposed to solve the problem of inconsistent responsivity of each pixel of the photodiode array. The sensitivity of the instrument is 6.75×10 -6 refractive index unit, measured with various concentrations of glycerol solution. Multiplex nucleic acid hybridization takes 30 minutes, and the biosensor can be regenerated over 50 times, with low-performance loss and good repeatability and specificity. The instrument has a limit of detection (LODs) of 50nM for target oligonucleotides, and the smallest detectable absolute amount of the sample is about 4 pmol. It provides a simple and efficient POCT detection platform for the detection of small molecules such as DNA and miRNA.