A silver nanoparticle-modified evanescent field optical fiber sensor for methylene blue detection

• Published in: Sensors (Basel, Switzerland) Vol. 13; no. 3; pp. 3986 - 3997
• Main Authors: Luo, Ji, Yao, Jun, Lu, Yonggang, Ma, Wenying, Zhuang, Xuye
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 21.03.2013; Molecular Diversity Preservation International (MDPI)
• Subjects: Biosensing Techniques - instrumentation; Biosensors; evanescent field optical fiber sensors; Gold; MEMS microchannel chip; Methylene Blue - isolation & purification; methylene blue detection; Micro-Electrical-Mechanical Systems - instrumentation; Microfluidic Analytical Techniques; Nanoparticles; Nanoparticles - chemistry; Optical Fibers; Optics; sensitivity; Sensors; Silver; Silver - chemistry; silver nanoparticles; China
• ISSN: 1424-8220; 1424-8220
• DOI: 10.3390/s130303986

A silver nanoparticle-modified evanescent field optical fiber sensor based on a MEMS microchannel chip has been successfully fabricated. Experimental results show that the sensor response decreases linearly with increasing concentration of analyte. Over a range of methylene blue concentrations from 0 to 0.4 μmol/mL, the sensor response is linear (R = 0.9496). A concentration variation of 0.1 μmol/mL can cause an absorbance change of 0.402 dB. Moreover, the optical responses of the same sensing fiber without decoration and modified with silver nanoparticles have also been compared. It can be observed that the output intensity of the Ag nanoparticle-modified sensor is enhanced and the sensitivity is higher. Meanwhile, the absorbance spectra are found to be more sensitive to concentration changes compared to the spectra of the peak wavelength.