Home-Based Electrochemical Rapid Sensor (HERS): A Diagnostic Tool for Bacterial Vaginosis

• Published in: Sensors (Basel, Switzerland) Vol. 23; no. 4; p. 1891
• Main Authors: Banks, Melissa, Amirghasemi, Farbod, Mitchell, Evelyn, Mousavi, Maral P S
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 01-02-2023; MDPI
• Subjects: Animals; Bacteria; bacterial vaginosis; Body Fluids; Borates; Carbon black; Chloride; Cotton; Deionization; Diagnosis; Electric properties; Electrodes; Female; female reproductive health; Fertility; Flowers; Gynecology; Health aspects; HIV; Human immunodeficiency virus; Humans; Infection; Infections; Infertility; Lab-on-a-chip; Odors; point-of-care sensor; Potassium; potentiometry; Pregnancy; Premature birth; Sensors; Sexual intercourse; Smell; Sodium; thread-based sensor; Trimethylamine; Vagina; Vaginosis; Vaginosis, Bacterial - diagnosis; VOCs; Volatile organic compounds; Womens health; Yarn; trimethylamine; point-of-care sensor; thread-based sensor; female reproductive health; potentiometry; bacterial vaginosis
• ISSN: 1424-8220; 1424-8220
• DOI: 10.3390/s23041891

Bacterial vaginosis (BV) is the most frequently occurring vaginal infection worldwide, yet it remains significantly underdiagnosed as a majority of patients are asymptomatic. Untreated BV poses a serious threat as it increases one's risk of STI acquisition, pregnancy complications, and infertility. We aim to minimize these risks by creating a low-cost disposable sensor for at-home BV diagnosis. A clinical diagnosis of BV is most commonly made according to the Amsel criteria. In this method, a fish-like odor, caused by increased levels of trimethylamine (TMA) in vaginal fluid, is used as a key diagnostic. This paper outlines the development of a Home-Based Electrochemical Rapid Sensor (HERS), capable of detecting TMA in simulated vaginal fluid (sVF). Instead of odor-based detection of volatilized TMA, we identify TMA in trimethylammonium form by utilizing HERS and a potentiometric readout. We fabricated the ion selective electrode using a carbon-black-coated cotton string and a TMA-selective membrane consisting of calix[4]arene and sodium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate. When paired with a standard reference electrode, our device was able to quantify TMA concentration in deionized (DI) water, as well as sVF samples at multiple pH levels with a clinically relevant limit of detection (8.66 µM, and theoretically expected Nernstian slope of 55.14 mV/decade).