Development of a Novel Electrochemical Biosensor Based on Carbon Nanofibers–Cobalt Phthalocyanine–Laccase for the Detection of p-Coumaric Acid in Phytoproducts

Abstract

The present paper developed a new enzymatic biosensor whose support is a screen-printed electrode based on carbon nanofibers modified with cobalt phthalocyanine and laccase (CNF-CoPc-Lac/SPE) to determine the p-coumaric acid (PCA) content by cyclic voltammetry and square wave voltammetry. Sensor modification was achieved by the casting and cross-linking technique, using glutaraldehyde as a reticulation agent. The biosensor’s response showed the PCA redox processes in a very stable and sensitive manner. The calibration curve was developed for the concentration range of p-coumaric acid of 0.1–202.5 μM, using cyclic voltammetry and chronoamperometry. The biosensor yielded optimal results for the linearity range 0.4–6.4 μM and stood out by low LOD and LOQ values, i.e., 4.83 × 10−7 M and 1.61 × 10−6 M, respectively. PCA was successfully determined in three phytoproducts of complex composition. The results obtained by the voltammetric method were compared to the ones obtained by the FTIR method. The amount of p-coumaric acid determined by means of CNF-CoPc-Lac/SPE was close to the one obtained by the standard spectrometric method.

Assessment of the Antioxidant Activity of Catechin in Nutraceuticals: Comparison between a Newly Developed Electrochemical Method and Spectrophotometric Methods

“…In the first stage of Lac reaction mechanism, an electron is donated to the substrate by the copper T1 site, followed by an internal electron transfer from the reduced copper T1 sites to the copper T2 and T3 sites [ 70 ]. Copper T3 functions as a two-electron acceptor in the aerobic oxidation process, in which the presence of copper T2 is required [ 71 ]. The reduction of oxygen to water occurs at the T2 and T3 sites, passing through a peroxide intermediate ( Figure 7 ) [ 72 ].…”

Evaluation of Olive Oil Quality with Electrochemical Sensors and Biosensors: A Review

“…The modifications made to the electrodes can have multiple benefits regarding the detection of polyphenols, but there is the possibility of certain limitations, as has been presented in the previous study, related to the contamination of the electrode surface due to the polymerisation of the oxidation product and the deposit of an insulating layer which will disturb a future reaction [ 147 , 148 ]. Consequently, the functioning of the electrode is an important stage, and the nanomaterials used must be adequately selected in view of increasing the sensitivity and selectivity of the sensor developed.…”

Carbon Nanomaterials (CNMs) and Enzymes: From Nanozymes to CNM-Enzyme Conjugates and Biodegradation

“…The most popular target molecule is glucose for biometric health monitoring ( Table 2 ) [ 224 , 227 , 228 , 237 , 249 , 269 , 271 , 273 ]. However, biosensors have been developed to detect many other bioactive compounds too, such as cholesterol [ 312 , 370 , 371 ] and triglycerides [ 282 ], lactose [ 220 ] and lactate [ 225 , 280 ], neurotransmitters [ 234 , 240 , 246 , 278 , 279 , 372 ] and hormones [ 239 ], various disease biomarkers [ 244 , 257 , 261 ], microRNAs [ 223 ], drugs [ 218 , 287 ], pathogens [ 219 ] and toxins [ 221 ], xanthine [ 262 ] and caffeic acid [ 373 ], p -coumaric acid [ 232 ], ferulic acid [ 233 ], trace metals [ 274 ], and oxygen [ 268 ].…”