Advanced Wave Sensors S.L. Paterna, 46988 Valencia, Spain.
Centro de Investigación e Innovación en Bioingeniería, Universitat Politècnica de València, 46022 Valencia, Spain.
Sensors (Basel). 2021 Jun 17;21(12):4166. doi: 10.3390/s21124166.
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.
整体式石英晶体微天平 (MQCM) 最近作为一种非常有前途的适用于生物传感应用的技术而出现。这些设备由集成在同一石英衬底内的微型化 QCM 传感器阵列组成，能够同时检测多个目标分析物。它们的相关优点包括高通量、每个传感器单元的低成本、低样品/试剂消耗和快速传感响应。尽管 MQCM 具有巨大的潜力，但不受欢迎的环境因素（例如温度、湿度、振动或压力）和传感器设置固有的干扰（例如测量单元施加的机械应力或表征系统的电子噪声）会影响传感器的稳定性，掩盖感兴趣的信号并降低检测限 (LoD)。在这里，我们提出了一种基于离散小波变换 (DWT) 的方法，以实时提高共振频率和耗散信号的稳定性。该方法利用集成在 MQCM 设备中的谐振器的噪声模式之间的相似性来减轻影响传感器响应的干扰因素。通过研究在外部控制因素（温度和压力/流速）下吸附蛋白质（亲和素和生物素化白蛋白）来验证该方法的性能，这些因素模拟了不希望出现的干扰。
