Simultaneous Determination of Different Phenolic Compounds Using Electrochemical Biosensor and Multivariate Calibration

Abstract

Phenolic compounds are important environmental contaminants due to their high toxicity and persistence in the environment. The use of enzyme-based electrochemical biosensors is a simple, sensitive and low-cost alternative for the determination of these pollutants in contaminated waters. However, in most cases, it is impossible to detect specific compounds in a mixture of phenols due to signal-overlap, as the instruments operate at very close potentials, given that the system is based on a single enzyme to detect similar structures. In order to overcome this problem, in the present work we have successfully used multivariate calibration with partial least squares (PLS) for the simultaneous determination of hydroquinone and guaiacol by a tyrosinase-based biosensor that was assembled using an enzyme extract from yam. The use of PLS allowed us to work with a large number of voltammograms, leading to a single mathematical model for the simultaneous determination of phenols of similar structure in real samples with concentration values of mmol L -1 .

Application of Chemometrics in Biosensing: A Brief Review

“…The optimized ANN with a linear transfer function resulted in a good prediction ability for all three phenolic compounds ( r > 0.988) on the external test set. Another approach to determine phenolic contaminants (hydroquinone and guaiacol) in water was recently proposed by Mendes and coworkers [ 16 ]. The tyrosinase-based enzymatic voltammetric biosensor was developed, and the PLS model with four latent variables was built to predict concentrations of two phenolic compounds simultaneously with R 2 > 0.99 and low relative error (1.3 to 4.4%) using cyclic voltammograms with 220 variables as the input data.…”

Biomarkers and biosensors for the diagnosis of noncompliant pH, dark cutting beef predisposition, and welfare in cattle

“…Moreover, the technique may be used for ketoacidosis detection in cattle — which may be linked to DC predisposition (see section 2.2)—through noninvasive saliva sampling. Another example is the differential determination of similar phenolic compounds (hydroquinone and guaiacol) by partial least square regression (PLS) with an enzymatic biosensor (such as a biosensor for succinate determination) that would normally not differentiate between these compounds due to signal overlap (Mendes et al., 2018). For amperometric sensors—mainly enzymatic biosensors such as sensors detecting succinate and glucose—chemometrics may greatly reduce noise and enhance sensitivity by differentiating capacitive current from Faradaic current.…”