Detection of 6-benzylaminopurine plant bioregulator using an opto-fluidic ring resonator (OFRR) biosensor

Abstract

The identification of the 6-benzylaminopurine (6-BAP) plant growth regulator was performed using a label-free opto-fluidic ring resonator (OFRR) biosensor. In this study, the OFRR biosensor with a BRIS sensitivity of 47.6 nm/RI was fabricated through the optimization of the manufacturing process of the OFRR capillary and a tapered fiber optic cable, which are the key components of the OFRR biosensor. The minimum detection concentration of 6-BAP standard solution and 6-BAP extracted from bean sprouts using QuEChERS method were 0.05 ppm in the fabricated OFRR biosensor system. In addition, the response signal was amplified up to sixfold through the application of a one-step sandwich assay that uses gold nanoparticles (AuNP) conjugated with anti-6-BAP to improve the measuring sensitivity of 6-BAP. As a result, the minimum detection concentration of 6-BAP was lowered to 0.01 ppm and it was possible to detect more segmented WGM spectral changes at lower concentrations.