Reusable surface plasmon resonance sensor for rapid detection of Cu2+ based on modified-chitosan thin film as an active layer

• Published in: Sensors and actuators. A. Physical. Vol. 286; pp. 59 - 67
• Main Authors: Wang, Wenhua, Zhou, Xinlei, Wu, Shengxu, Li, Sidong, Wu, Weina, Xiong, Zhengye, Shi, Wenqing, Tian, Xiuyun, Yu, Qingxu
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.02.2019
• Subjects: Composite film; Copper ions; Modified-chitosan; Reutilization; Surface plasmon resonance; Composite film; Reutilization; Modified-chitosan; Surface plasmon resonance; Copper ions
• ISSN: 0924-4247; 1873-3069
• DOI: 10.1016/j.sna.2018.12.025

•We proposed an improved SPR sensor used a semi-cylindrical prism to simplify the detection process.•The reutilization of SPR sensor based on four-layer Kretschmann configuration was achieved by EDTA solution.•The SPR sensors possess excellent stability, elution degree and rebirth power, and detection and elution times are fast.•The Ag/Au/MCS composite film configuration was proposed to enhance high sensitivity of trace Cu2+ determination.•The present SPR sensor exhibits a sensitivity of 0.7271 ppm−1 and a detection resolution of 18 ppb. In this article, a reusable surface plasmon resonance (SPR) sensor for rapid detection of copper ions (Cu2+), based on optimized silver/gold (Ag/Au) composite film modified by modified-chitosan (MCS) thin film as an active layer, was achieved. We employed a four-layer Kretchmann semi-cylindrical prism configuration and induced a reference beam into the experimental system to improve the sensitivity and stability, and investigated the cross-linking technique of CS solution, the spin coating process of MCS film, the stability of active layer, the rebirth power of SPR sensor, and the detection for trace Cu2+. The rate of swelling or dissolution of MCS film after flushing sensor chip for four times is less than 9×10−4/min, and the decline of signal value is less than 1.5% after MCS film adsorbing Cu2+ and multiple flushing. The elution and capacity rates are above 96% after five times of elution for the sensor by EDTA solution with 0.5mmol/L. Within 1-5ppm, the SPR sensor was found to possess sensitivity of 0.7271ppm−1. The LOD is 18ppb for the trace Cu2+. The present SPR sensor not only could be used in trace monitoring of Cu2+ but also could be extended to other potential applications.