Fiber optic particle plasmon resonance immunosensor for rapid and sensitive detection of methamphetamine based on competitive inhibition

Abstract

We report the study of methamphetamine (MA) sensing in urine samples using fiber optic particle plasmon resonance (FOPPR) biosensor. This approach is intended for on-site analysis of low-molecular-weight compounds. High sensitivity detection of MA at ultra-low concentration is realized by using a competitive inhibition immunoreaction scheme based on the competition of free MA in solution for anti-MA molecules that bind to the bovine serum albumin (BSA)–MA conjugate on the gold nanoparticle surface.With the BSA–MA functionalized sensor fiber, in the presence of a fixed concentration of anti-MA and various concentrations of MA in sample, the change of transmitted light intensity through the sensor fiber relative to that in a buffer solution decreases when the MA concentration increases because of the inhibition effect of MA. Based on this sensing method, the MA-functionalized FOPPR biosensor is capable for determining the concentration of MA with high sensitivity and wide linear dynamic range of 1–1000 ng/mL. The limit of detection for MA is 0.16 ng/mL. In addition, the MA functionalized FOPPR biosensor can detect MA in diluted human urine samples without nonspecific adsorption interference.