Point-of-Care Detection of Salivary Nitrite Based on the Surface Plasmon-Assisted Catalytic Coupling Reaction of Aromatic Amines

Abstract

Rapid quantification of nitrite (NO2−) in food, drink and body fluids is of significant importance for both food safety and point-of-care (POA) applications. However, conventional nitrite analytical methods are complicated, constrained to sample content, and time-consuming. Inspired by a nitrite-triggered surface plasmon-assisted catalysis (SPAC) reaction, a rapid point-of-care detection salivary nitrate was developed in this work. NO2− ions can trigger the rapid conversion of p-aminothiophenol (PATP) to p,p′-dimercaptozaobenzene (DMAB) on gold nanoparticles (GNPs) under light illumination, and the emerged new bands at ca. 1140, 1390, 1432 cm−1 originating from DMAB can be used to the quantification of nitrite. Meanwhile, to make the method entirely suitable for on-site fast screen or point-of-care application, the technique is needed to be further optimized. The calibration graph for nitrates was linear in the range of 1–100 µM with a correlation coefficient of 0.9579. The limit of detection was 1 µM. The facile method could lead to a further understanding of the progression and treatment of periodontitis and to guide professionals in planning on-site campaigns to effectively control periodontal diseases.

The Role of Sulfhydryl (Thiols) Groups in Oral and Periodontal Diseases

“…Disulfide bonds (S-S), formed during protein biosynthesis through the oxidation of sulfhydryl groups, play a crucial role in stabilizing protein structures, including enzymes, antibodies, and various hormones [71,72]. Disruption of disulfide bonds leads to the denaturation of protein structures and the loss of biological activity [73][74][75][76]. These bonds significantly contribute to the tertiary structure of proteins.…”

Rapid and Specific Enhanced Luminescent Switch of Aniline Gas by MOFs Assembled from a Planar Binuclear Cadmium(II) Metalloligand

“…However, to date, the analytical tools exploited for the detection of amines such as chromatography, electrophoretic methods, and mass spectroscopy suffer from many shortcomings, for instance, expensive instrumentation, time-consuming procedures, and complicated operation, which have made them unsuitable for on-site and quick detection. Meanwhile, fluorescence detection which has been proved to be a sensitive, convenient, and fast detection method gets more and more attention, and research and many materials have been developed for the VOC luminescent sensing. − At room temperature, due to the low vapor pressure of aromatic amines, most of the reported fluorescence detections of aromatic amines are under a liquid condition but relatively few under a gaseous condition. − In addition, compared to the fluorescence quenching (turn-off) detection, the fluorescence enhancement (turn-on) detection is more attractive and rare. Therefore, designing and developing the materials for fluorescence enhancement response of aromatic amine vapors are progressing with an extraordinary effort.…”

Wooden Tongue Depressor Multiplex Saliva Biosensor Fabricated via Diode Laser Engraving

“…Proof-of-principle applicability of these devices is demonstrated for the amperometric determination of nitrite and glucose in artificial saliva. Both nitrite and glucose are significant biomarkers, as salivary nitrite can be used to detect oral diseases (e.g., periodontitis), − while salivary glucose can be used as a diagnostic biomarker for diabetic patients. − …”