Transmission surface plasmon resonance imaging based on gold grating/silver nanoparticles for detection of creatinine

Abstract

In diagnostics analysis, creatinine is a biomarker for the evaluation of renal and muscular dystrophy in various biology and closely related to the life activities of the organism. In this research, we investigated the transmission surface plasmon resonance-imaging (TSPR-i) with a 3-channel microfluidic cell. TSPR-i based on the exploitation of propagating SPR is the technique for monitoring the changes in surface plasmon resonance of gold film on both glass slide substrates and diffraction gold grating substrates to their surrounding environments in transmission configuration. The silver nanoparticles (AgNPs) were deposited with poly (diallydimethylammonium chloride) (PDADMAC) and poly (sodium 4-styrenesulfonate) (PSS) using layer-by-layer (LbL) technique on gold thin film grating/substrate surfaces for the detection of creatinine. In this experiment, the TSPR-i signal was detected by a camera coupled with liquid crystal tunable filters (LCTF). The TSPR-i signal of Au grating dominated at the incident angle of ∼35 degree and a strong excitation wavelength was observed at ∼720 nm. After the deposition of AgNPs on the gold grating substrate, the TSPR-i intensity decreased and then increased again when incubated with creatinine for 1 h. In addition, TSPR-i technique was used to study the effect of localized surface plasmon resonance (LSPR) from plasmonic AgNPs on the gold-grating/dielectric interface for the signal enhancement of creatinine. The 5-bilayer of AgNPs/PDADMAC film onto 10 bi-layer of PDADMAC/PSS intermediate layers on BK7 glass slides before and after injection of creatinine was studied by UV-vis absorption spectroscopy. The creatinine sensor exhibited good sensitivity toward the determination of creatinine and showed a linear calibration range from 0.1 to 20 mM. A simple, and cost-effective method has been demonstrated on the TSPR imaging system for real-time, label-free, good sensitive which will be potentially useful for clinical applications.