A Novel Conductometric Urea Biosensor with Improved Analytical Characteristic Based on Recombinant Urease Adsorbed on Nanoparticle of Silicalite

Abstract

Development of a conductometric biosensor for the urea detection has been reported. It was created using a non-typical method of the recombinant urease immobilization via adsorption on nanoporous particles of silicalite. It should be noted that this biosensor has a number of advantages, such as simple and fast performance, the absence of toxic compounds during biosensor preparation, and high reproducibility (RSD = 5.1 %). The linear range of urea determination by using the biosensor was 0.05-15 mM, and a lower limit of urea detection was 20 μM. The bioselective element was found to be stable for 19 days. The characteristics of recombinant urease-based biomembranes, such as dependence of responses on the protein and ion concentrations, were investigated. It is shown that the developed biosensor can be successfully used for the urea analysis during renal dialysis.

Acoustic Wave Catalyzed Urea Detection Utilizing a Pulsatile Microdroplet Sensor

“…The kinetics data for the reaction have been presented in Table 1. formation of ions in the solution 61 contributed to the further reduction in the electrical resistance across the droplet upon sound exposure. Thus, during the sensing process, the reduction in the electrical resistance across the droplet happened due to the combined influence of the salt loading as well as the generation of additional NH 4 + ions from the urea−urease reaction, apart from the reasons discussed previously.…”

“…48,50,51 For the normal functioning of the human body, the acceptable range of urea in blood serum is around 15−40 mg/dL (or 2.5−7.5 mmol/L). 52,53 In order to detect the urea concentrations in the body fluids, a variety of sensors have been developed over the years based on different sensing principles such as electro-chemiluminescence, 54 electrochemical techniques, 55−58 aptasensors, 59 piezoelectric sensors, 60 conductometric detectors, 61,62 organic field effect transistors (OFET) devices, 63 and potentiometric 64 or amperometric techniques. 65 However, all of the abovementioned methodologies are reported to have certain issues associated with either the response time, portability, specificity, selectivity, or ecofriendliness.…”