Plug-in optical fiber SPR biosensor for lung cancer gene detection with temperature and pH compensation

A novel DNA hybridization optical fiber sensor with temperature and pH compensation for detecting a common lung cancer gene of epidermal growth factor receptor (EGFR) gene was demonstrated in this paper. The paper proposes the first research to achieve dual surface plasmon resonance (SPR) in an Fiber Bragg grating (FBG) and implement a three-parameter detection of DNA sequence, temperature and pH using a single fiber. Probe DNA sequences (pDNA) and PAA/CS, a pH-sensitive material, are immobilized on the sensor surface for EGFR gene exon-20 detection and temperature and pH monitoring simultaneously. The effectiveness of this functionalized method has been proved by using an atomic force microscope (AFM) and scanning electron microscope (SEM). The limit of detection (LOD) of EGFR gene was experimentally verified to 13.5 nM. The advantages of fast response, high sensitivity, label free, plug in, low LOD and three-parameter detection demonstrated by this sensor in the experiment are important for the field of DNA hybridization research and solving the problems of biosensor susceptibility to temperature and pH.