Escherichia coli Based Microfluidic Whole-cell Glucose Biosensor
Treatment of diabetes and its complications is a major challenge in India owing to several issues, including sociocultural factors, lack of appropriate facilities for diabetes care, an inadequate health system, poor monitoring and follow-up of patients, and problems in implementing effective management and educational strategies. Healthcare professionals and policymakers have to come together to address these problems in diabetes care and design appropriate preventative and management strategies. We present a novel method, wherein a low cost glucose biosensor can be developed using the synergy of microfluidics technology and molecular biology. The Lac Operon has to do with the ability of E. coli to utilize the sugar lactose. Glucose is a very efficient carbon source; it can enter directly into the metabolic paths that provide both energy and substrates for making more complex compounds. If lactose is provided as the carbon source, it must first be broken down into the two component sugars before it can be used. The cell preferentially takes up glucose first and then lactose as an alternative.X-gal ( 5-bromo-4-chloro-3-indolyl-β-D-galactopyranoside) a lactose analogue and IPTG (isopropyl beta-D-thio-galactoside) Inducer for Beta-Galactosidase Expression is provided along with a prepared glucose sample to a fresh culture of E.coli. The E.coli uses up the glucose first and then the lactose. The glucose provided is of differential concentrations ranging from 0-10ul. After the glucose reserves are used up ,the organism utilizes lactose and produces a slight tint of blue due to the cleavage of lactose into galactose and glucose. Based on the different concentrations we can obtain a linear curve and can determine the concentration of glucose.
We inculcate this principle into the microfluidics arena, as microfluidics allows reagents to react in minute regimes. We have developed a PDMS based microfluidics device which consists of wells for input of reagents and an outlet which is attached to a filter paper which takes up the product and acts as a matrix for the representation of the colour. If this device and it’s techniques of operation are tweaked and optimized then it can be a very fine candidate for entry into the genre of “Low-Cost Glucose Detection Devices”.