Results of the studies are reported relating to application of the silanized nanostructured zirconia, electrophoretically deposited onto indium tin oxide (ITO) coated glass for covalent immobilization of the monoclonal antibodies (anti‐CYFRA‐21‐1). This biosensing platform has been utilized for a simple, efficient, noninvasive, and label‐free detection of oral cancer via cyclic voltammetry technique. The results of electrochemical response studies conducted on bovine serum albumin (BSA)/anti‐CYFRA‐21‐1/3‐aminopropyl triethoxy silane (APTES)/ZrO2/ITO immunoelectrode reveal that this immunoelectrode can be used to measure CYFRA‐21‐1 (oral cancer biomarker) concentration in saliva samples, with a high sensitivity of 2.2 mA mL ng−1, a linear detection range of 2–16 ng mL−1, and stability of six weeks. The results of these studies have been validated via enzyme‐linked immunosorbent assay.

Please cite this article as: Thien-Toan Tran, Ashok Mulchandani, Carbon nanotubes and graphene nano field-effect transistor-based biosensors, Trends in Analytical Chemistry (2016), http://dx.doi.org/

In the United States (U.S.), up to 14% of the population depend on private wells as their primary drinking water source. The U.S. government does not regulate contaminants in private wells. The goals of this study were to investigate the quality of drinking water from unregulated private wells within one mile (1.6 kilometers) of an effluent-dominated river in the arid Southwest, determine differences in contaminant levels between wet and dry seasons, and identify contributions from human sources by specifically measuring man-made organic contaminants (perfluorooctanoic acid (PFOA), perfluorooctane sulfate (PFOS), and sucralose). Samples were collected during two dry seasons and two wet seasons over the course of two years and analyzed for microbial (Escherichia coli), inorganic (arsenic, cadmium, chromium, copper, lead, mercury, nitrate), and synthetic organic (PFOA, PFOS, and sucralose) contaminants. Arsenic, nitrate, and Escherichia coli concentrations exceeded their respective regulatory levels of 0.01 mg/L, 10 mg/L, and 1 colony forming unit (CFU)/100 mL, respectively. The measured concentrations of PFOA and PFOS exceeded the respective Public Health Advisory level. Arsenic, PFOA, PFOS, and sucralose were significantly higher during the dry seasons, whereas E. coli was higher during the wet seasons. While some contaminants were correlated (e.g., As and Hg ρ = 0.87; PFOA and PFOS ρ = 0.45), the lack of correlation between different contaminant types indicates that they may arise from different sources. Multi-faceted interventions are needed to reduce exposure to drinking water above health-based guidelines.

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Carbon nanotubes (CNT) are a family of carbon nanomaterials that have uses in many technological and medical applications due to their unique properties. However, compared to other nanomaterials, CNT have a significantly lower specific surface areas (SSA), which is a critical limitation for applications. To overcome this limitation, here, we report a new protocol to synthesize a hybrid material composed of varying ratios of multiwalled carbon nanotubes (MWCNT) and ferrihydrite (FHY). Furthermore, through a series of physical and electrochemical characterization tests, we determined that 36% FHY and 64% MWCNT is the optimum ratio for a composite that maximizes both SSA and specific capacitance. The calculated SSA of the composite was 190 m2·g−1, 2.9 times higher than that of MWCNT alone. Moreover, the composite retained valuable electrochemical properties of CNT with an estimated specific capacitance of 100 F·g−1. This composite is a promising multifunctional nanomaterial for environmental and technological applications requiring electrochemical reactivity and high specific areas such as environmental biosensors, and capacitive deionization for wastewater remediation, and water softening.