A One-Step Electropolymerized Biomimetic Polypyrrole Membrane-Based Electrochemical Sensor for Selective Detection of Valproate

Abstract

Bipolar disorder is a chronic mental disease with a heavy social and economic burden that causes extreme mood swings in patients. Valproate is a first-line drug for bipolar disorder patients to stabilize their daily mood. However, an excessive amount of valproate in the blood could induce severe adverse effects, which necessitates the monitoring of blood valproate levels for patients. Here, we developed an innovative electrochemical sensor for selective and simple detection of valproate based on a molecularly imprinted polymer membrane via one-step electropolymerization. Gold nanoparticles were electrochemically modified to the screen-printed electrode under the selective membrane to enhance its conductivity and stability. The successfully fabricated biosensor was characterized by scanning electron microscopy, cyclic voltammetry, and differential pulse voltammetry methods. The binding of the target molecules to the valproate-customized biomimetic polypyrrole membrane blocks cavities in the membrane and alters its electric properties, which can be detected as a decrease in the peak current by differential pulse voltammetry method. The peak current change presents a great log-linear response to the valproate concentration around the therapeutic window. The limit of detection of this method was 17.48 μM (LOD, S/N = 3) and the sensitivity was 31.86 μM μA−1. Furthermore, the biosensors exhibited both satisfying specificity with the interference of other psychological pharmaceutical drugs and uniformity among sensors, indicating their potential and reliability in translational application. This simple and reliable method of sensing valproate molecules primarily provides an exceptional solution to valproate point-of-care testing in clinical practice.

Screen-printed electrode designed with MXene/doped-polyindole and MWCNT/doped-polyindole for chronoamperometric enzymatic glucose sensor

“…In addition, the anodic and cathodic peak currents of the κC-GOD/MWCNT-dPIn (I pa = 263.5 μA and I pc = −93.1 μA) are higher than those of SPCE (I pa = 81.1 μA and I pc = −77.5 μA) implying that the electrical conductivity of the modified electrode was improved. The results of CV are consistent with the SPCE modified with a composite of CNTs-gold nanoparticles [ 55 ], and the SPE modified with a composite of PPy-AuNPs [ 56 ]. The increase of ΔE p after the GOD immobilization indicates the slower electron transfer as a result of the non-electrical layers of both CHI-GOD and κC-GOD increasing the electrode resistance [ 57 ].…”

Recent Advances in Conductive Polymers-Based Electrochemical Sensors for Biomedical and Environmental Applications

“…However, elevated levels of valproic acid in the bloodstream can lead to severe adverse reactions, necessitating regular monitoring of blood valproic acid concentrations in patients [ 129 ]. Yuan et al, developed an innovative electrochemical sensor for the selective and facile detection of valproate, utilizing a molecularly imprinted polymer film prepared via one-step electro-polymerization [ 130 ]. The binding of the target molecule to the custom bionic PPy membrane of valproic acid obstructs the cavity within the membrane and induces alterations in its electrical properties, which can be detected through differential pulse voltammetry (DPV) as a reduction in peak current.…”