Functional Optical Immunosensor Microfluidic Platform for Acute Myocardial Infarction Diagnosis

摘要

Cardiovascular disease (CVD), the leading cause of death worldwide, has been viewed as one of the major problems forwealthy and industrialized nations for decades, and the need for rapid detection and timely diagnosis has the utmostimportance. Cardiac troponin I (cTnI) is a promising biomarker for early diagnosis of acute myocardial infarction (AMI) .Hence, the development of immunoassay based biosensor for cTnI is necessary. Over the past decades, there have beenextensive researches regarding cTnI detection, including colorimetric, fluorescence, paramagnetic, electrochemical, andsurface plasmon resonance. However, conventional laboratory methods are time-consuming and require expensive andbulky equipment. In light of this, the need for point of care testing becomes more crucial. Here, we use a programmablemicrocontroller unit (MCU) to operate the device. A digital-to-analog converter (DAC) is used to deliver a modulatingsignal to LEDs, and then the modulated light excites the samples in the microfluidic reaction wells. The signals from thesample and control group are obtained by two photodetectors individually. They will be amplified and demodulatedthrough the lock-in amplifier and digitized by analog-to-digital converters (ADC) to the MCU. And the collected data willbe presented on the device and uploaded synchronically to the smartphone via Bluetooth. The whole processing time isless than 5 minutes. Next, we use the microfluidic platform to simplify complicated laboratory procedures. In our study,we focus on using cTnI to detect the samples in the human serum or blood. In order to solve low efficacy caused by thenon-specific binding, we used Zwitterionic carboxybetaine disulfide (CB) as a self-assembled monolayer in theexperimental design. The use of self-assembled monolayer can not only decrease non-specific binding problem but alsoshorten the analysis time.