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

Chemosensors ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 159
Author(s):  
Satit Rodphukdeekul ◽  
Miyuki Tabata ◽  
Chindanai Ratanaporncharoen ◽  
Yasuo Takeuchi ◽  
Pakpum Somboon ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Quartz Crystal Microbalance ◽  
Quantitative Assessment ◽  
Quartz Crystal ◽  
Dynamic Range ◽  
Gold Surface ◽  
Enzyme Linked Immunosorbent Assay ◽  
Inflammatory Disorder ◽  
Label Free ◽  
Periodontal Bacteria

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.

Evaluation of Performance of a Commercial Monoclonal Antibody–Based Fenitrothion Immunoassay and Application to Residual Analysis in Fruit Samples

2006 ◽  
Vol 69 (1) ◽  
pp. 191-198 ◽  
Author(s):  
EIKI WATANABE ◽  
KOJI BABA ◽  
HEESOO EUN ◽  
TOMOHITO ARAO ◽  
YASUO ISHII ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Dynamic Range ◽  
Limit Of Detection ◽  
Close Correlation ◽  
Gas Chromatography Mass Spectrometry ◽  
Enzyme Linked Immunosorbent Assay ◽  
High Recovery ◽  
Elisa Kit ◽  
Fruit Samples ◽  
Standard Solutions

The performance of a commercially available enzyme-linked immunosorbent assay (ELISA) kit containing highly sensitive monoclonal antibodies against fenitrothion was assessed. The experimentally estimated dynamic range (0.087 to 2 ng/g) agreed with that established by the kit manufacturer (0.075 to 1 ng/g). The linearity of the standard curve produced for the kit-assembled standard solutions (slope = −0.3829) agreed with that of the curve produced for the self-made standard solutions (slope =−0.3619). The sensitivity (I50 value) and the limit of detection for the kit were 0.23 and 0.033 ng/g, respectively. Selectivity of the ELISA indicates that the monoclonal antibody can readily distinguish the target pesticide from other structurally related analogs and some metabolites (oxon forms), with the exception of ethyl O-(p-nitrophenyl) phenyl phosphonothionate (EPN), parathion-methyl, and parathion. Methanol was the best organic solvent for the kit, with optimal sensitivity observed at a final concentration in the well of 10% (vol/vol) or less. Matrix interferences were minimized by direct dilution with water (60-fold) of the methanolic extracts from apple and peach samples. To extract fenitrothion from these two agricultural products as simply and rapidly as possible, three extraction methods were used. The extraction method that involved shaking by hand for 3 min was the best among the three methods. High recovery percentages (116.6% for apple and 110.8% for peach) were obtained. Validation of the ELISA method was carried out using the gas chromatography–mass spectrometry method, resulting in high recovery and close correlation of results (r > 0.95). These findings strongly suggest that the ELISA kit may be routinely employed for on-site fenitrothion screening of fruit samples.

scholarly journals Rapid and Simultaneous Quantification of 4 Urinary Proteins by Piezoelectric Quartz Crystal Microbalance Immunosensor Array

2006 ◽  
Vol 52 (12) ◽  
pp. 2273-2280 ◽  
Author(s):  
Yang Luo ◽  
Ming Chen ◽  
Qianjun Wen ◽  
Meng Zhao ◽  
Bo Zhang ◽  
...  
Keyword(s):  
Quartz Crystal Microbalance ◽  
Quartz Crystal ◽  
Clinical Chemistry ◽  
Label Free ◽  
Urinary Proteins ◽  
Quartz Crystals ◽  
Piezoelectric Quartz ◽  
Piezoelectric Immunosensor ◽  
Highly Sensitive ◽  
Piezoelectric Quartz Crystal

Abstract Background: Urinary proteins are predictive and prognostic markers for diabetes nephropathy. Conventional methods for the quantification of urinary proteins, however, are time-consuming, and most require radioactive labeling. We designed a label-free piezoelectric quartz crystal microbalance (QCM) immunosensor array to simultaneously quantify 4 urinary proteins. Methods: We constructed a 2 × 5 model piezoelectric immunosensor array fabricated with disposable quartz crystals for quantification of microalbumin, α1-microglobulin, β2-microglobulin, and IgG in urine. We made calibration curves after immobilization of antibodies at an optimal concentration and then evaluated the performance characteristics of the immunosensor with a series of tests. In addition, we measured 124 urine samples with both QCM immunosensor array and immunonephelometry to assess the correlation between the 2 methods. Results: With the QCM immunosensor array, we were able to quantify 4 urinary proteins within 15 min. This method had an analytical interval of 0.01–60 mg/L. The intraassay and interassay imprecisions (CVs) were <10%, and the relative recovery rates were 90.3%–109.1%. Nonspecificity of the immunosensor was insignificant (frequency shifts <20 Hz). ROC analyses indicated sensitivities were ≥95.8% and, specificities were ≥76.3%. Bland–Altman difference plots showed the immunosensor array to be highly comparable to immunonephelometry. Conclusions: The QCM system we designed has the advantages of being rapid, label free, and highly sensitive and thus can be a useful supplement to commercial assay methods in clinical chemistry.

Determination of Albumin in Urine by a Quartz Crystal Microbalance Label-Free Assay

2017 ◽  
Vol 50 (12) ◽  
pp. 1912-1925 ◽  
Author(s):  
Watcharinthon Theansun ◽  
Jittawat Sripratumporn ◽  
Chamras Promptmas
Keyword(s):  
Quartz Crystal Microbalance ◽  
Quartz Crystal ◽  
Label Free

scholarly journals A Novel Signal-Amplified Immunoassay for the Detection of C-Reactive Protein Using HRP-Doped Magnetic Nanoparticles as Labels with the Electrochemical Quartz Crystal Microbalance as a Detector

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Ning Gan ◽  
Ping Xiong ◽  
Ji Wang ◽  
Tianhua Li ◽  
Futao Hu ◽  
...  
Keyword(s):  
Quartz Crystal Microbalance ◽  
Quartz Crystal ◽  
Microtiter Plate ◽  
Electrochemical Quartz Crystal Microbalance ◽  
Magnetic Core ◽  
Enzyme Linked Immunosorbent Assay ◽  
C Reactive Protein ◽  
Reactive Protein ◽  
Insoluble Product

A novel horseradish peroxidase- (HPR-) doped magnetic core-shell Fe3O4@SiO2@Au nanocomposites (Fe-Au MNPs) were employed on immunoassay for the determination of C-reactive protein (CRP) based on a electrochemical quartz crystal microbalance detector (EQCM). Firstly, the secondary CRP antibody and HRP were both immobilized on the Fe-Au MNPs (Fe-Au MNPs-anti-CRP2/HRP) as a signal tag. Secondly, the above tag and the primary antibody (anti-CRP1) in the bottom of 96-well microtiter plate were employed to conjugate with a serial of CRP concentrations to produce a sandwich immunocomplex. Thirdly, the immunocomplex solution was subsequently exposed to3,3′-diaminobenzidine (DAB) in the presence of H2O2, resulting in an insoluble product. When the precipitation solution was dripped on EQCM, it can achieve a decrease of frequency of crystal (Δf). The amount ofΔfwas proportional to (CRP) from 0.003 to 200 ng mL−1with a low detection limit of 1 pg mL−1. Compared with the enzyme-linked immunosorbent assay (ELISA), the immunoassay shows greatly improved sensitivity due to the significant amount of HRP labeled on signal tag. It also has good specificity and low sample consumption, which is expected to be a benefit for the CRP screening in early diagnosis of cardiovascular disease.

Diagnosis and genotyping of Plasmodium falciparum by a DNA biosensor based on quartz crystal microbalance (QCM)

2011 ◽  
Vol 49 (8) ◽  
Author(s):  
Tiparat Potipitak ◽  
Warunee Ngrenngarmlert ◽  
Chamras Promptmas ◽  
Sirinart Chomean ◽  
Wanida Ittarat
Keyword(s):  
Quartz Crystal Microbalance ◽  
Malaria Infection ◽  
Quartz Crystal ◽  
High Sensitivity ◽  
Cost Effective ◽  
Dna Biosensor ◽  
Dual Function ◽  
Label Free ◽  
Free Dna ◽  
Nanogram Level

AbstractMalaria infection withA label-free DNA biosensor based on quartz crystal microbalance (QCM) to diagnose and genotypeThe newly developed QCM was tested for its diagnosis ability using both malaria laboratory strains and clinical isolates. The biosensor was sensitive at the sub-nanogram level, specific for onlyThe dual function QCM was successfully developed with high sensitivity and specificity, and was cost-effective, stable and field adaptable.

Fabrication of hydroxyapatite ultra-thin layer on gold surface and its application for quartz crystal microbalance technique

Biomaterials ◽  
2006 ◽  
Vol 27 (33) ◽  
pp. 5748-5754 ◽  
Author(s):  
Akira Monkawa ◽  
Toshiyuki Ikoma ◽  
Shunji Yunoki ◽  
Tomohiko Yoshioka ◽  
Junzo Tanaka ◽  
...  
Keyword(s):  
Thin Layer ◽  
Quartz Crystal Microbalance ◽  
Quartz Crystal ◽  
Gold Surface
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