Lipase Assisted Improved RF Biosensor for Triglycerides Level Detection in Blood Serum

Blood cholesterol and triglycerides are vital indicators of heart functioning, as their abnormal values can cause atherosclerosis resulting into conditions like hypertension, cerebrovascular accident, etc. Conventional enzyme-based spectroscopy employed in pathological laboratories necessitate complicated steps involving several extra-pure reagents, expensive instruments, and highly skilled professionals. In this work, a novel RF biosensor with high quality factor (Q) and improved sensitivity is proposed for detection of various solutes such as glucose, electrolytes, lipid profile etc., in human blood. The proposed RF sensor is based on the substrate integrated waveguide (SIW) technology to acquire an enhanced Q of 390. The sensitivity of the proposed biosensor for estimation of Triglycerides mixture (TM) in blood serum is substantially enhanced using the Lipase enzyme as a bioreceptor. Various parameters of the proposed RF SIW sensor structure are optimized using the CST-MWS software, and the designed sensor is fabricated on 1.6 mm thick Taconic (TLY-5) substrate using the photolithography technique. The fabricated RF biosensor is tested using the network analyzer to monitor the transmission coefficient in the S-band frequency range, which provides an enhanced sensitivity of 0.554 MHz/mg.dL ⁻¹ for triglyceride levels in blood serum. The proposed RF biosensor with Lipase as a bioreceptor is able to detect the triglyceride concentrations of 150 mg/dL and 200 mg/dL (i.e., healthy, and border-line triglyceride limits) in blood serum, which makes it ideally suited for estimation of various solutes in the blood plasma.