POC-System for on-chip electrochemical detection of pathogens for treatment of periodontitis

Abstract

Periodontitis is a widespread inflammatory disease of the oral cavity that demands rapid and accurate diagnostic methods to improve clinical outcomes. Point-of-care (POC) biosensors offer a promising approach for the timely detection of periodontal pathogens directly in dental practices. This study presents the characterization of newly developed microfluidic FoldChips employing enzyme-based DNA detection using two analytical techniques: electrochemical (EC) and chemiluminescence (CL) based detection. Measurement protocols, signal analysis methods, and calibration models were established for both detection methods. The FoldChip system was evaluated using DNA standards specific to Aggregatibacter actinomycetemcomitans, Prevotella intermedia (Pi), Porphyromonas gingivalis (Pg), Treponema denticola (Td), Tannerella forsythia (Tf), and total germ load (TGL), as well as with viable cells of Escherichia coli (E. coli) and Pi. Both EC and CL modes achieved dynamic ranges of 0.01–25 nM and limits of detection (LOD) below 1.2 nM. However, CL provided higher consistency and sensitivity for DNA standards, with LODs of 12–55 pM (excluding Pi), while EC demonstrated a broader LOD range of 23 pM–1.2 nM, with the best-performing probes yielding LODs of 23 pM (Pg), 26 pM (Tf), and 31 pM (TGL). In cell-based assays, EC detection showed approximately tenfold greater sensitivity compared to CL, achieving LODs of 2.2 · 103 cells/L (TGL, E. coli) and 5.6 · 105 cells/L (Pi), versus 9.71 · 104 cells/L and 1.96 · 106 cells/L for CL, respectively. These results demonstrate the FoldChip as a versatile and sensitive platform for periodontal pathogen detection, compatible with both EC and CL readouts. Its multiplexing capability and potential for integration into compact POC systems highlight its promise for future clinical diagnostics in periodontology.

Periodontitis is a widespread inflammatory disease of the oral cavity that demands rapid and accurate diagnostic methods to improve clinical outcomes. Point-of-care (POC) biosensors offer a promising approach for the timely detection of periodontal pathogens directly in dental practices. This study presents the characterization of newly developed microfluidic FoldChips employing enzyme-based DNA detection using two analytical techniques: electrochemical (EC) and chemiluminescence (CL) based detection. Measurement protocols, signal analysis methods, and calibration models were established for both detection methods. The FoldChip system was evaluated using DNA standards specific to Aggregatibacter actinomycetemcomitans, Prevotella intermedia (Pi), Porphyromonas gingivalis (Pg), Treponema denticola (Td), Tannerella forsythia (Tf), and total germ load (TGL), as well as with viable cells of Escherichia coli (E. coli) and Pi. Both EC and CL modes achieved dynamic ranges of 0.01–25 nM and limits of detection (LOD) below 1.2 nM. However, CL provided higher consistency and sensitivity for DNA standards, with LODs of 12–55 pM (excluding Pi), while EC demonstrated a broader LOD range of 23 pM–1.2 nM, with the best-performing probes yielding LODs of 23 pM (Pg), 26 pM (Tf), and 31 pM (TGL). In cell-based assays, EC detection showed approximately tenfold greater sensitivity compared to CL, achieving LODs of 2.2 · 103 cells/L (TGL, E. coli) and 5.6 · 105 cells/L (Pi), versus 9.71 · 104 cells/L and 1.96 · 106 cells/L for CL, respectively. These results demonstrate the FoldChip as a versatile and sensitive platform for periodontal pathogen detection, compatible with both EC and CL readouts. Its multiplexing capability and potential for integration into compact POC systems highlight its promise for future clinical diagnostics in periodontology.