Quantitative Assessment of Periodontal Bacteria Using a Cell-Based Immunoassay with Functionalized Quartz Crystal Microbalance

• Published in: Chemosensors Vol. 9; no. 7; p. 159
• Main Authors: Rodphukdeekul, Satit, Tabata, Miyuki, Ratanaporncharoen, Chindanai, Takeuchi, Yasuo, Somboon, Pakpum, Boonlue, Watcharee, Miyahara, Yuji, Sriyudthsak, Mana
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01-07-2021
• Subjects: Antibodies; Bacteria; Bacterial infections; Biosensors; Carbodiimide; Disease; Electrodes; Enzyme-linked immunosorbent assay; Enzymes; Ethanol; Gold; Immunoassay; immunoassays; Immunosensors; Inflammatory diseases; Microbalances; Monoclonal antibodies; Packing density; Pathogens; periodontal bacteria; Periodontal disease; Periodontal diseases; Periodontitis; Quantitative analysis; Quartz; Quartz crystal microbalance; quartz crystal microbalance biosensors; Quartz crystals; Self-assembled monolayers; Self-assembly; Sensors; Teeth; United Kingdom > UK; United States > US; Japan
• ISSN: 2227-9040; 2227-9040
• DOI: 10.3390/chemosensors9070159

Periodontal disease is an inflammatory disorder that is triggered by bacterial plaque and causes the destruction of the tooth-supporting tissues leading to tooth loss. Several bacteria species, including Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans, are considered to be associated with severe periodontal conditions. In this study, we demonstrated a quartz crystal microbalance (QCM) immunoassay for quantitative assessment of the periodontal bacteria, A. actinomycetemcomitans. An immunosensor was constructed using a self-assembled monolayer of 11-mercaptoundecanoic acid (11-MUA) on the gold surface of a QCM chip. The 11-MUA layer was evaluated using a cyclic voltammetry technique to determine its mass and packing density. Next, a monoclonal antibody was covalently linked to 11-MUA using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide to act as the biorecognition element. The specificity of the monoclonal antibody was confirmed by an enzyme-linked immunosorbent assay. A calibration curve, for the relationship between the frequency shifts and number of bacteria, was used to calculate the number of A. actinomycetemcomitans bacteria in a test sample. Based on a regression equation, the lower detection limit was 800 cells, with a dynamic range up to 2.32 × 106 cells. Thus, the QCM biosensor in this study provides a sensitive and label-free method for quantitative analysis of periodontal bacteria. The method can be used in various biosensing assays for practical application and routine detection of periodontitis pathogens.