Development of biosensor-based tools to detect carcinogenic precursors from saliva and gastric juice to prevent stomach cancer disparities among Hispanic
Introduction
According to the American Cancer Society, the risk of stomach cancer among Hispanic people is three times higher than that of Non-Hispanic White (NHW) people. Among many other reasons, H. pylori infection rate is found to be strongly correlated with the rate of stomach cancer diagnoses among Hispanics. One of the H. pylori metabolites, called nitroso compounds, are known to be highly carcinogenic and are the most significant reason for developing stomach cancer among the low-income communities, including Hispanics. In this project, we aim to develop and utilize an electrochemical immunosensing platform for early diagnosis of stomach cancer precursor by measuring N-nitrosodipropylamine (NDPA), one of the carcinogenic nitroso compounds, concentrations.
Methods
A porous carbon confined CuCo bimetallic system was synthesized with a total of three varying ratios of Cu and Co ions via high temperature pyrolysis technique. The efficacy and validity of the sensor for detecting NDPA was studied using CV (cyclic voltammetry), EIS (electrochemical impedance spectroscopy), and DPV (differential pulse voltammetry) techniques.
Results
A porous carbon confined CuCo bimetallic system was synthesized with a total of three varying ratios of Cu and Co ions via high temperature pyrolysis technique. The efficacy and validity of the sensor for detecting NDPA was studied using CV (cyclic voltammetry), EIS (electrochemical impedance spectroscopy), and DPV (differential pulse voltammetry) techniques. The limit of detection (LOD) for GCE (glassy carbon electrode) in a PBS (phosphate buffered saline) solution of pH 5 was recorded as 1.6 nM, while for SPCE (screen printed carbon electrode) the LOD in the same solution was recorded at 0.19 nM. The applicability of the sensor for detecting NDPA was tested with simulated gastric fluid (SGF). Finally, real sample analysis via DPV technique was conducted with saliva and gastric juice collected from human donors at MD Anderson Cancer Center.
Conclusion
The sensitivity, experimental stability, and reproducibility offer the potential to translate the proposed platform as a point-of-care gastric cancer detection device. Therefore, we envision that with further improvement, optimization, and validation this portable, cost-effective, and ease-of-use point-of-care device can be used for identifying individuals who are at risk of stomach cancer due to H. pylori infection. With early detection and identification, this screening technology can be used to prevent stomach cancer prevalence and save thousands of individuals.