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The ability to rapidly and reliably screen for bacterial vaginosis (BV) during pregnancy is of great significance for maternal health and pregnancy outcomes. In this proof-of-concept study, we demonstrated the potential of carbon nanotube field-effect transistors (NTFET) in the rapid diagnostics of BV with the sensing of BV-related factors such as pH and biogenic amines. The fabricated sensors showed good linearity to pH changes with a linear correlation coefficient of 0.99. The pH sensing performance was stable after more than one month of sensor storage. In addition, the sensor was able to classify BV-related biogenic amine-negative/positive samples with machine learning, utilizing different test strategies and algorithms, including linear discriminant analysis (LDA), support vector machine (SVM), and principal component analysis (PCA). The biogenic amine sample status could be well classified using a soft-margin SVM model with a validation accuracy of 87.5%. The accuracy could be further improved using a gold gate electrode for measurement, with accuracy higher than 90% in both LDA and SVM models. We also explored the sensing mechanisms and found that the change in NTFET off current was crucial for classification. The fabricated sensors successfully detect BV-related factors, demonstrating the competitive advantage of NTFET for point-of-care diagnostics of BV.

A series of A7-substituted A"'-hydroxyureas and Ar'-hydroxythioureas were prepared, and their inhibitory properties have been examined in several microbial systems. The hydroxythiourea analogs proved to be toxic to growth of Lactobacillus arabinosus, Leuconostoc dextranicum, and Streptococcus faecalis at about 2 ug mi: however, the growth inhibition was reversed by adding supplements of cysteine and other sulfhydryl compounds not of natural origin. The toxicity of these derivatives may be due to protein denaturation since in an isolated enzyme system (yeast alcohol dehydrogenase) the enzyme is progressively deactivated by increasing concentrations of A'-substituted A7 '-hydroxythioureas, and the toxicity is negated by the presence of a variety of SH compounds.

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