Love Wave Surface Acoustic Wave Sensor with Laser-Deposited Nanoporous Gold Sensitive Layer.

Viespe Viespe,Dinca Dinca,Popescu-Pelin Popescu-Pelin,Miu Miu

doi:10.3390/s19204492

Viespe Viespe, Dinca Dinca + Show 2 more

Open Access

https://doi.org/10.3390/s19204492

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Abstract

Laser-deposited gold immobilization layers with different porosities were incorporated into Love Wave Surface Acoustic Wave sensors (LW-SAWs). Acetylcholinesterase (AChE) enzyme was immobilized onto three gold interfaces with different morphologies, and the sensor response to chloroform was measured. The response of the sensors to various chloroform concentrations indicates that their sensing properties (sensitivity, limit of detection) are considerably improved when the gold layers are porous, in comparison to a conventional dense gold layer. The results obtained can be used to improve properties of SAW-based biosensors by controlling the nanostructure of the gold immobilization layer, in combination with other enzymes and proteins, since the design of the present sensor is the same as that for a Love Wave biosensor.

Highlights

Gas sensors are used in numerous domains such as the detection of Chemical Warfare Agents (CWA), control of emissions or monitoring of various hazardous gases [1,2]
It has been reported that in certain conditions the morphology of polymer films can change through viscous flow, as a result of gold nanoparticles being sputter-deposited onto their surface [40,41]
The nanoporous gold layers on the Surface Acoustic Wave sensors (SAWs) sensors which were tested were deposited at a higher deposition pressure of 4 Torr, which leads to a lower energy of the incident species due to hydrodynamic effects in the laser ablation plasma [32]

Summary

Introduction

Gas sensors are used in numerous domains such as the detection of Chemical Warfare Agents (CWA), control of emissions or monitoring of various hazardous gases [1,2]. Several types of gas sensors are currently used, such as resistive sensors, optical devices or Surface Acoustic Wave sensors (SAWs) [5,6,7]. SAW sensors present a series of advantages such as high sensitivity, fast response, reliability, ease of fabrication, and low cost [7,8,9]. The sensitivity is a result of the detection mechanism, which is based on perturbation of the SAW propagation, primarily by mechanical or acoustoelectric effects, in the presence of the analyte [10]. In addition to applications in gas sensing, SAW sensors have been used in Love Wave (LW)

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