Fiber optic biosensor for detection of genetically modified food based on catalytic hairpin assembly reaction and nanocomposites assisted signal amplification

Abstract

A novel fiber optic surface plasmon resonance (FOSPR) biosensor was developed first time for qualitative and quantitative detection of transgenic components in food based on the catalytic hairpin assembly (CHA) reaction and AuNPs-rGO nanocomposites assisted signal amplification strategy. Unlike the traditional CHA, the assay incorporated a special CHA, in which two-base mismatches between HP1 and HP2 were designed to achieve ultrasensitive detection of the target chain with high content of guanine (G) and cytosine (C). Under the optimized conditions, the SPR resonance wavelength exhibited a good linear relationship with the target chain extracted from genetically modified (GM) food in the range of 0.5–500nM with the detection and quantification limits of 12pM (S/N=3) and 40pM (S/N=10), respectively. Moreover, the proposed method could discriminate two-base non-complementary targets. This biosensing strategy exhibits good reproducibility and precision, and has been successfully applied for detection of target DNA in complex genetically modified food. In addition, the CHA based SPR biosensing methodology is extended to the detection of other substances by aptamer recognition. Thus, the versatile method might become a potential alternative tool for biomolecule detection in food analysis and early clinical diagnosis.