Tyrosinase-Based Biosensor—A New Tool for Chlorogenic Acid Detection in Nutraceutical Formulations

Abstract

The purpose of our research was to develop a new enzymatic biosensor, GPH-MnPc-Tyr/SPE, using as a support screen-printed carbon electrode (SPE) modified with graphene, manganese phthalocyanine, and tyrosinase, with the aim of developing sensitive detection of chlorogenic acid (CGA). To immobilise tyrosinase on the sensor surface, crosslinking with the glutaraldehyde technique was used, thus increasing the enzyme bioactivity on this electrode. The modified electrode has a great catalytic effect on the electrochemical redox of chlorogenic acid, compared to the simple, unmodified SPE. The peak current response of the biosensor for CGA was linear in the range of 0.1–10.48 μM, obtaining a calibration curve using cyclic voltammetry (CV) and square-wave voltammetry (SWV). Subsequently, the detection limit (LOD) and the quantification limit (LOQ) were determined, obtaining low values, i.e., LOD = 1.40 × 10−6 M; LOQ = 4.69 × 10−6 M by cyclic voltammetry and LOD = 2.32 × 10−7 M; LOQ= 7.74 × 10−7 M, by square-wave voltammetry (SWV). These results demonstrate that the method is suitable for the detection of CGA in nutraceutical formulations. Therefore, GPH-MnPc-Tyr/SPE was used for the quantitative determination of CGA in three products, by means of cyclic voltammetry. The Folin–Ciocalteu spectrophotometric assay was used for the validation of the results, obtaining a good correlation between the voltammetric method and the spectrophotometric one, at a confidence level of 95%. Moreover, by means of the DPPH method, the antioxidant activity of the compound was determined, thus demonstrating the antioxidant effect of CGA in all nutraceuticals studied.

Electrochemical Characterization Using Biosensors with the Coagulant Moringa oleifera Seed Lectin (cMoL)

“…Electroanalytical methods such as cyclic voltammograms using electrodes modified with nanocomposites are increasingly being required to identify the redox properties of biomolecules [67], such as MOFs, due to their biocompatibility for glucose and H2O2 detection [43]. In this work, through a voltammogram, the treatment efficiency was observed due to the difference in the redox peaks, for which there was a decrease in the current peaks in the treated samples, indicating that cMoL was able to monitor the residues before and after the treatment.…”

Studies on the Detection of Oleuropein from Extra Virgin Olive Oils Using Enzymatic Biosensors

“…By analyzing the evolution of the cathodic currents, it was determined that there is a linear dependence between the cathodic currents and the scan rate ( Figure 6 ) in both cases, suggesting that the process at the active surface of the electrospray is predominantly controlled by the oleuropein adsorption process. Several papers have reported this electrochemical behaviour of enzyme biosensors [ 86 , 87 , 88 ].…”

Antioxidant Determining Using an Electrochemical Method

“…The obtained biosensor results were subjected to comparison with the spectrophotometric method. The two methods yielded comparable validation outcomes, indicating that the biosensor approach for analyzing chlorogenic acid in nutraceutical products is characterized by high selectivity, rapid response, and holds the potential for monitoring phenolic compounds [82].…”