Development of a new two‐enzyme biosensor based on poly(pyrrole‐co‐3,4‐ethylenedioxythiophene) for lactose determination in milk

Abstract

A new lactose biosensor was developed by preparing a suitable copolymer of polypyrrole and poly(3,4-ethylenedioxythiophene) synthesized using the electropolymerization method. Pyrrole and 3,4-ethylenedioxythiophene monomers were deposited in the presence of sodium dodecylbenzene sulphonic acid on a platinum disc electrode, which was used as the working electrode. The sensor is based on the serial reactions of b-galactosidase and galactose oxidase immobilized on a copolymermodified platinum disc electrode. Successful synthesis of the enzyme-immobilized copolymer was confirmed by FT-IR spectrometry, SEM, and electrochemical analysis. The response of the enzyme electrode to lactose was determined by cyclic voltammetry at 1 0.40 V. The response time of the biosensor was found to be from 8 to 10 s, and the upper limit of the linear working portion was found to be at a lactose concentration of 2.30 mM with a detection limit of 1.4 3 10 25 M. The apparent Michaelis-Menten constant was found to be 0.65 mM of lactose. The effects of interferents were also investigated. Lactose concentrations determined by the biosensor were in good agreement with those measured by the reference methods. Our results show that the developed biosensor has a significant potential to the determination of lactose concentration in milk.

Recent developments in conducting polymers: applications for electrochemistry

“…According to the outputs, this new biosensor had remarkable potential for determining the concentration of lactose in milk. 84 Researchers modied a commercially available SPCE with the MWCNTs, AuNPs, as well as the poly-neutral red (PNR) lm. Aerwards, the electrode was modied with the alcohol dehydrogenase (ADH) for use in the procurement process of the disposable amperometric biosensor to analyze ethanol.…”

Facile and Low-Cost SPE Modification Towards Ultra-Sensitive Organophosphorus and Carbamate Pesticide Detection in Olive Oil

“…Amongst them, electrochemical enzyme-based biosensors are especially suited for field applications since they are easy to manufacture, require low sample volumes (typically in the order of µL), have a short analysis time and have the ability to be integrated into compact and portable analysis devices [ 10 ]. Recently they have been used for the detection of pesticides in several real samples and complex matrices, such as tap water [ 11 ], vegetables [ 12 ], fruits, milk [ 13 ] and olive oil [ 14 ]. Their principle of operation relies on the inhibitory effects different pesticides have on enzymes.…”

Electrochemically Produced Copolymers of Pyrrole and Its Derivatives: A Plentitude of Material Properties Using “Simple” Heterocyclic Co-Monomers

“…Immobilized enzymes (β-galactosidase and galactose oxidase) were also employed for the detection of lactose in milk, with a copolymer of Py and 3,4-ethylenedioxythiophene (EDOT) being used as the immobilizing matrix [ 99 ]. The produced bio-sensors were found to respond rapidly (response time of 8–10 s) and featured an excellent detection threshold of 0.014 mM lactose.…”