Integrated Biosensor with Microfluidic Chip and Microwave Sensor Chip for Cell Separation and Detection

Abstract

In this work, an integrated biosensor consisting of spiral microfluidic array and microwave sensors is proposed for simultaneous separation and detection of cells. The biosensor integrated by plasma processing technology is fabricated by soft lithography and glass-based IC process, which has the advantages of simple preparation, low cost, and reliable structure. In the field of clinical medicine, Escherichia coli (E. coli) is the causative agent of urinary tract infections, which leads to an increase in the number of white blood cells (WBCs) present in the urine. Different concentrations of E. coli and WBCs mixed solution are configured to perform biological cell experiments and the capability of the biosensor in separating and detecting WBCs is verified. Interdigital capacitors (IDCs) and split ring resonators (SRRs) are employed to detect the WBCs obtained by microfluidic array separation. The microfluidic array exhibits a WBC collection rate of 92.7%. The capacitance of the IDC and the resonant amplitude of the SRR exhibit a decrease of 51.36 pF and 0.34 dB, which demonstrates a satisfactory linearity of 0.96 and 0.98, respectively. Consequently, the integrated biosensor used to simultaneously separate and detect WBCs has the potential for the early diagnosis of urinary tract infections in clinical medicine.