Myeloperoxidase as a biomarker in periodontal disease: electrochemical detection using printed screen graphene electrodes

Abstract

Periodontal disease is a common oral health issue marked by inflammation and the breakdown of tissues. Early detection of biomarkers associated with periodontal disease (PD) can significantly aid in timely diagnosis and intervention. Myeloperoxidase (MPO) is an enzyme abundantly present in neutrophils and has been associated in the pathogenesis of PD. Here, we present a novel approach for the electrochemical detection of MPO using printed screen graphene electrodes coupled with principal component analysis (PCA) for data analysis. We employed cyclic voltammetry to characterize the electrochemical behavior of MPO using potassium ferrocyanide and hydrogen peroxide. The process was controlled by species diffusion on the electrode surface using a scan rate spanning from 10 to 400 mVs^-1. In addition, we investigated the detection of hydrogen peroxide, a substrate of MPO, as a method to indirectly asses MPO electroactivity, leveraging a redox potential of - 500 mV. Saliva samples were collected and analyzed using the developed electrochemical sensor, followed by principal component analysis to differentiate between healthy and diseased samples based on MPO levels. Our findings demonstrate the feasibility of using printed screen graphene electrodes for the sensitive and selective detection of MPO, offering a promising approach for early diagnosis and monitoring of periodontal disease. In conclusion, our results highlight the potential of MPO as a robust biomarker for periodontal disease and highlight the utility of electrochemical sensing coupled with PCA analysis for sensitive and specific detection in clinical settings.

Keywords: Cyclic voltammetry; Myeloperoxidase; Periodontal disease; Screen-printed graphene electrodes; Sensor.

Fig. 1

Catalytic cycle of MPO

Fig. 2

Cyclic voltammograms (A) and scan rate root vs cathodic and anodic currents (B) of MPO-SPGE with H₂O₂ 0.05 mM in 100 mM PBS pH 7.2 at different scan rates (10, 50, 100, 150, 200, and 400 mV/s)

Fig. 3

A CVs of MPO-SPGE at different concentrations of H₂O₂ (0.05, 0.1, 0.25, 0.5, 1, and 2 mM), scan rate 0.15 mV/s, B CVs of modified (green) and unmodified SPGE in the presence of 0.5 mM

Fig. 4

CVs of SPGE modified with saliva sample in the presence (purple) and absence (green) of H₂O₂. Inset: detail of CV of SPGE without H₂O₂. Scan rate 0.15 mV/s

Fig. 5

A CVs for MPO present in 3 saliva samples; B intensity of the current for bioelectrocatalytic reduction of H₂O₂ by MPO present in 3 saliva samples at three different levels of PD (HG healthy gingiva, no periodontal disease; G gingivitis and P periodontitis)

Fig. 6

PCA of saliva samples using SPGE