A Real-Time Method for Improving Stability of Monolithic Quartz Crystal Microbalance Operating under Harsh Environmental Conditions.

Román Fernández,Antonio Arnau,Yolanda Jiménez,María Calero

doi:10.3390/s21124166

Román Fernández, Antonio Arnau + Show 2 more

Open Access

https://doi.org/10.3390/s21124166

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Abstract

Monolithic quartz crystal microbalance (MQCM) has recently emerged as a very promising technology suitable for biosensing applications. These devices consist of an array of miniaturized QCM sensors integrated within the same quartz substrate capable of detecting multiple target analytes simultaneously. Their relevant benefits include high throughput, low cost per sensor unit, low sample/reagent consumption and fast sensing response. Despite the great potential of MQCM, unwanted environmental factors (e.g., temperature, humidity, vibrations, or pressure) and perturbations intrinsic to the sensor setup (e.g., mechanical stress exerted by the measurement cell or electronic noise of the characterization system) can affect sensor stability, masking the signal of interest and degrading the limit of detection (LoD). Here, we present a method based on the discrete wavelet transform (DWT) to improve the stability of the resonance frequency and dissipation signals in real time. The method takes advantage of the similarity among the noise patterns of the resonators integrated in an MQCM device to mitigate disturbing factors that impact on sensor response. Performance of the method is validated by studying the adsorption of proteins (neutravidin and biotinylated albumin) under external controlled factors (temperature and pressure/flow rate) that simulate unwanted disturbances.

Highlights

Conventional analytical methods currently employed as a “gold standard” require trained personnel in centralized laboratories to perform time-consuming experiments with costly, large, and bulky devices
quartz crystal microbalance (QCM) parameter that provides information about viscoelastic and conformational characteristics of the sample, all methods we found in the literature are focused exclusively on improving the quality of the resonance frequency
We presented a method that exploits the high level of correlation found in the response of the acoustic wave sensors integrated in an Monolithic quartz crystal microbalance (MQCM) device to minimize the impact of unwanted disturbances on the stability and reliability of the measurement

Summary

Introduction

Conventional analytical methods currently employed as a “gold standard” require trained personnel in centralized laboratories to perform time-consuming experiments with costly, large, and bulky devices. Owing to their simplicity, reduced size, good sensitivity and low cost, novel biosensors may play a fundamental role in the very near future, becoming an alternative analytical tool in health care, food security and environmental monitoring applications. Novel transducers are continuously emerging, electrochemical, optical and acoustic transducers are the most popular ones These three approaches are well-established technologies with their advantages and drawbacks (see references [1,2] for more information)

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