Development of amperometric biosensor in modified carbon paste with enzymatic preparation based on lactase immobilized on carbon nanotubes.

Autor: de Brito AR; Departament of Natural Sciences and Exact, State University of Southweast Bahia, Itapetinga, Bahia 45700-000 Brazil., Dos Santos Reis N; Departament of Natural Sciences and Exact, State University of Southweast Bahia, Itapetinga, Bahia 45700-000 Brazil., Oliveira PC; Departament of Natural Sciences and Exact, State University of Southweast Bahia, Itapetinga, Bahia 45700-000 Brazil., Rezende DVB; Departament of Natural Sciences and Exact, State University of Southweast Bahia, Itapetinga, Bahia 45700-000 Brazil., Monteiro GP; Departament of Natural Sciences and Exact, State University of Southweast Bahia, Itapetinga, Bahia 45700-000 Brazil., Soares GA; 2Departament of Exact Sciences and Technology, State University of Santa Cruz, Ilhéus, Bahia 45662-900 Brazil., de Jesus RS; 2Departament of Exact Sciences and Technology, State University of Santa Cruz, Ilhéus, Bahia 45662-900 Brazil., Santos AS; 2Departament of Exact Sciences and Technology, State University of Santa Cruz, Ilhéus, Bahia 45662-900 Brazil., Salay LC; 2Departament of Exact Sciences and Technology, State University of Santa Cruz, Ilhéus, Bahia 45662-900 Brazil., de Oliveira JR; 2Departament of Exact Sciences and Technology, State University of Santa Cruz, Ilhéus, Bahia 45662-900 Brazil., Franco M; 2Departament of Exact Sciences and Technology, State University of Santa Cruz, Ilhéus, Bahia 45662-900 Brazil.
Jazyk: angličtina
Zdroj: Journal of food science and technology [J Food Sci Technol] 2020 Apr; Vol. 57 (4), pp. 1342-1350. Date of Electronic Publication: 2019 Nov 11.
DOI: 10.1007/s13197-019-04168-9
Abstrakt: Abstract: The variety of products derived from milk, without or with lactose, encourages the development of more effective analytical techniques that can be applied to the quality control of both the production line and the final products. Thus, in this work an efficient and minimally invasive method for the detection of lactose was proposed, using a biosensor containing the enzyme lactase (LAC) immobilised on carbon nanotubes (CNTs) that, when reacting with lactose, emit an electrochemical signal. This biosensor was connected to a potentiostat, and its electrochemical cell was composed of the following three electrodes: reference electrode (Ag/AgCl), auxiliary electrode (platinum wire), and working electrode (biosensor) on which graphite (carbon) paste (CP), CNTs, and LAC were deposited. The transmission electron microscopy and scanning electron microscopy were used in the characterisation of the composite morphology, indicating excellent interactions between the CNTs and LAC. The sensitivity of the CP/LAC/CNT biosensor was determined as 5.67 μA cm -2 .mmol -1  L and detection limits around 100 × 10 -6  mol L -1 (electrode area = 0.12 cm 2 ) and an increase in the stability of the system was observed with the introduction of CNTs because, with about 12 h of use, there was no variation in the signal (current). The results indicate that the association between the CNTs and LAC favoured the electrochemical system.
(© Association of Food Scientists & Technologists (India) 2019.)
Databáze: MEDLINE
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