98%
921
2 minutes
20
A biosensor for arsenite has been developed using molybdenum-containing arsenite oxidase, prepared from the chemolithoautotroph NT-26 that oxidizes arsenite to arsenate. The enzyme was galvanostatically deposited for 10 min at 10 microA onto the active surface of a multiwalled carbon nanotube modified glassy carbon electrode. The resulting biosensor enabled direct electron transfer, i.e., effecting reduction and then reoxidization of the enzyme without an artificial electron-transfer mediator. Arsenite was detected within 10 s at an applied potential of 0.3 V with linearity up to 500 ppb and a detection limit of 1 ppb. The biosensor exhibited excellent reproducibility, 2% at 95% confidence interval for 12 repeated analyses of 25 ppb arsenite. Copper, a severe interfering species commonly found in groundwater, did not interfere, and the biosensor was applicable for repeated analysis of spiked arsenite in tap water, river water, and a commercial mineral water.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/ac070766i | DOI Listing |
Environ Sci Technol Lett
August 2024
School of Civil and Environmental Engineering, Cornell University, Ithaca, New York, 14853, United States.
Arsenic methylation is the microbe-mediated transformation of inorganic As into methylated species, an important component of the biogeochemical arsenic cycle in rice paddies. Prior to methylation, arsenite is taken up into bacterial cells through GlpF, an aquaglyceroporin channel for uptake of glycerol and other low-molecular-weight organics. The uptake and subsequent biotransformation of arsenite are therefore linked to the bacterial utilization of organics.
View Article and Find Full Text PDFNat Commun
July 2025
Rice University, Houston, TX, USA.
To advance environmental health and hazard detection, researchers have developed whole-cell bioelectronic sensors by engineering extracellular electron transfer to be dependent on an analyte. However, these sensors regulate a single electron transfer pathway as an electrochemical channel, limiting the sensing information to a single analyte. We have developed a multichannel bioelectronic sensor where different chemicals regulate distinct extracellular electron transfer pathways within a single Escherichia coli cell.
View Article and Find Full Text PDFAnal Chim Acta
May 2025
State Key Laboratory of Radiation Medicine and Protection, Soochow University, Suzhou, 215123, China. Electronic address:
Background: Current available detection methods can not afford the direct and precise detection of trace arsenite (As(III)) in high-salinity water bodies. Therefore, the development of device with low limit of detection (LOD) for the early detection of As(III) in high-salinity water samples is of vital importance to secure environment and food safety.
Results: Herein, we report a rapid and visualized device for trace As(III) determination in practical water samples by DNA aptasensor based electrochemiluminescence (ECL) method.
Biosens Bioelectron
March 2025
Shenzhen Bay Laboratory, Shenzhen, 518132, China. Electronic address:
Here, we developed nanobody-assisted nanoluciferase fragment complementation for in situ measurement and visualization of endogenous protein-protein interaction (NanaPPI). When an interaction occurs, primary antibodies for two proteins bring the proximity of secondary nanobody-fused small/large fragment to reassemble into an intact NanoLuc variant, thus transforming interaction events to luminescent signals in situ with high sensitivity. Compared to proximity ligation assay, NanaPPI has a similar signal-to-background ratio, but it is more convenient with faster procedures, easier readout and lower cost.
View Article and Find Full Text PDFFood Chem
October 2024
Department of Food Science & Technology, School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Minhang District, Shanghai 200240, China. Electronic address:
Arsenite (As), a highly carcinogenic heavy metal ion and widely distributed in nature, can have serious health implications even with minimal exposure. Herein, a portable smartphone device-based ratiometric fluorescence platform was established for sensitive detection of As. The work relied on the use of metal-organic framework-tagged cDNA (PCN-224-cDNA), with high adsorption capability and fluorescence properties, as an internal reference to quench the fluorescence of FAM-anchored aptamer (FAM-Apt) via hybridization.
View Article and Find Full Text PDF