Regenerable Biosensor Research Articles

Regenerable myoglobin biosensor based on protein G immobilized on interdigitated electrodes

A simple, sensitive and regenerable biosensor was developed for determining the concentration of myoglobin (Myo). Protein G was employed as an antibody-linking agent, which affords oriented antibody immobilization and the ability to regenerate the sensor. The Myo-antibody of anti-Myo-IgG was immobilized on the protein G layer with its Fc binding domain facing the solution side and thus its orientation allowed easy access for Myo molecules. Electrochemical impedance spectroscopy was used to evaluate the Myo sensor performance. The sensor was able to detect Myo between 10 pg ml−1 and 1 μg ml−1. Regeneration of the sensor was achieved by immersing the electrodes in 0.2 M glycine buffer and by immobilizing fresh antibodies in neutral buffer. The response of the regenerated sensor to Myo was 65% that of the response of the initial sensor.

Regenerable Plasmonic Biosensor Based on Gold Nanolines Pattern and Common Laboratory Spectrophotometer

Gold nanostructures can undergo plasmonic behavior without need of light couplers like in traditional surface plasmon resonance (SPR) systems. This effect, known as LSPR (localized SPR), can be exploited to develop optical biosensors in simple configuration. In this paper, an LSPR system based on gold lines nanopattern as transducer has been developed by using a common laboratory spectrophotometer as reader and an adapted flow cell. This novel system was applied to anti-immunoglobulin G (IgG) detection, as proof of concept. For this purpose, the transducer surface was covalently biofunctionalized with IgG and incubated with increasing concentrations of anti-IgG. The response was determined by measuring changes in light transmission spectra (Δλ, in nanometers). Contrary to other reported nanopatterns, biosensor features as repeatability, regeneration, and detectability have been deeply studied. Results indicate that the system can act as a robust and regenerable biosensor with a limit of detection of 5.98 ± 1.34 nM.

A sensitive and regenerable biosensor for organophosphate pesticide based on self‐assembled multilayer film with CdTe as fluorescence probe

A fluorescence biosensor for organophosphorus pesticides was developed. A pH indicator, CdTe quantum dots, were used as an optical transducer of the inhibition of enzyme by analyte. Through the intervening agency of chitosan, the recognition elements (acetylcholinesterase and CdTe) were immobilized onto the surface of quartz by electrostatic attraction to form a self-assembled multilayer film. In the absence of pesticide, acetylcholine was biocatalytically hydrolysed to yield acetic acid and choline. The released acid resulted in pH decrease, which was sensed by the immobilized pH indicator (CdTe). In the presence of pesticide, the action of acetylcholine was reduced; the fluorescence intensity of the film changed and was related to the concentration of pesticide. This multilayer film could be used as the biosensor for monocrotophos, with a detection limit of 3.20 × 10(-8) mol/L; the sensitivity was 100 times higher than that of CdTe in aqueous solution. The sensor was easily regenerated, and had good stability and selectivity for organophosphorus pesticides.

Synergistic pH effect for reversible shuttling aptamer-based biosensors between graphene oxide and target molecules

DNA aptamers are known to desorb from graphene oxide (GO) surface in the presence of target molecules. We demonstrate herein that the binding equilibrium can be shifted by simply tuning the solution pH. At lower pH, the aptamer/GO binding is enhanced while aptamer/target binding is weakened, making this system a regenerable biosensor without covalent conjugation.

Technology for Regenerable Biosensor Probes Based on Enzyme‐Cellulose Binding Domain Conjugates

AbstractThe application of enzyme‐based biosensors for on‐line bioprocess monitoring and control has been slowed by problems relating to the in situ sterilizability of the probe and the stability of the enzyme component. A novel technology with the potential to address both of these difficulties is presented here. The approach is based on the reversible immobilization of enzymes conjugated with the cellulose binding domain (CBD) of cellulases from Cellulomonas fimi. A regenerable biosensor electrode can be configured with a cellulose matrix onto which the enzyme‐CBD conjugate can be repeatedly loaded (bound by the CBD) and subsequently eluted by perfusing the cellulose matrix with the appropriate solution. Glucose oxidase (GOx) conjugated to CBD with glutaraldehyde was used in an experimental glucose biosensor to demonstrate the feasibility of multiple cycles of loading and elution of the conjugate. Michaelis‐Menten enzyme kinetics provided an empirical model for the calibration of the experimental biosensor. The development of a computer‐controlled prototype glucose biosensor and a fermentation monitoring system based on this approach is discussed.