Prototype of Optical Fiber biosensor for the real time detection of urea

Sneha Patil; Yogendra Ramtirtha; Milind Kulkarni; Meena Karve; Ayesha Khan

Volume : X, Issue : VIII, August - 2020

Prototype of Optical Fiber biosensor for the real time detection of urea

Sneha Patil, Yogendra Ramtirtha, Milind Kulkarni, Meena Karve, Ayesha Khan

Abstract :

Background & Objective: In recent years, there has been a growing impetus in the development of biosensors for medical and biological applications. Various gastrointestinal and urinary tract infections and renal disorders lead to increased blood urea concentrations which require immediate follow–up. This paper reports a low–cost urease sensor for rapid urea detection by immobilizing the enzyme urease on optical fiber by covalent attachment using poly vinyl alcohol (PVA) with glutaraldehyde. Method: The enzyme was partially purified from Dolichos biflorus seeds and further immobilized for biosensor construction. Two techniques viz. entrapment and covalent attachment were employed wherein the later was found to be a better method. The response of the biosensor for different concentrations of urea was monitored by measuring optical losses by using a power meter. Result: The prototype constructed displayed a linear decrease in the reflectance measured in decibel with increasing urea concentration. The response time of the constructed biosensor was 30 secs and the lower detection limit was observed to be 2 x 10–6M. A linear response for a wide range of urea concentrations viz. 2 μM to 50 mM was obtained. Interpretation & conclusion: The highlight of this biosensor is that it works on partially purified enzyme urease and a minimum volume of 10 μl is required for the detection of urea in sample.