Development of a high analytical performance-tyrosinase biosensor based on a composite graphite–Teflon electrode modified with gold nanoparticles

Substrate-dependent kinetics in tyrosinase-based biosensing: amperometry vs. spectrophotometry

“…Tyrosinase has broad substrate specificity toward phenols relevant for a wide range of applications [11]. The enzymatic reaction of phenols can be monitored by various electrochemical detection techniques, including detection of dioxygen consumption [12], direct reduction of generated o-quinone [13], and coupled mediated reduction of o-quinone [14]. Among these methods, amperometric detection of the biocatalytically generated o-quinones is most common.…”

Graphite-Composites Alternatives for Electrochemical Biosensor

“…A total of four electrochemical sensors were made using different composites: carbon paste, GEC and Teflon/Graphite, to which different enzymes were added to the bulk mixture (see Figure 2). The composition of the composites were selected among successful combinations in the literature (Bojorge et al, 2007;Carralero et al, 2006), and according to preliminary exploratory experiments in our laboratory. ., 2007] and a specific mass of 0.050g of Tyrosinase (Sigma) and HRP (Toyobo-Brazil) in a mortar for at least 20 min.…”

“…From this mother pellet, several cylindrical portions of each pellet are bored, and each portion is press-fitted into a Teflon holder. Electrical contact is made through a stainless steel screw (Carralero et al, 2006).…”

Gold Nanoparticles-Enhanced Amperometric Tyrosinase Biosensor Based on Three-Dimensional Sol-Gel Film-Modified Gold Electrodes

“…A relative standard deviation (RSD) of 3.5% has been observed for ten successive determination of 0.1 mM catechol, indicating the reliable reproducibility of the sensor. The analytical performance of the tyrosinase-based biosensor was compared with those reported for other recent tyrosinase-based biosensor, [33][34][35][36][37] as can been seen in Table 1. It can be deduced that the developed tyr/AuNPs/MTPS/Au biosensor allows a wide range of linearity, and provides a fast current response.…”

“…At present, an electrochemical biosensor has been proven to be an accurate and versatile analytical method for the detection of phenolic compounds, due to such advantages as high selectivity, relatively low cost, and the miniaturization and automation. [1][2][3] More recently, various supporting materials, such as graphite composite, 4 conducting polymer, 5,6 sol-gel films, 7,8 and self-assembled monolayers (SAMs), 9 have been successfully utilized to immobilize enzymes for the construction of a tyrosinase (tyr)-based electrochemical biosensor. Among them, sol-gel film offers a better biointerface for the immobilization of enzymes.…”