Pulse-opencircuit voltammetry: A novel method characterizes bioanode performance from microbe-electrode interfacial processes

Dominating Contribution of Intracellular Electron Generation over Extracellular Electron Transfer in Signaling Toxic Formaldehyde Exposure in Electrochemically Active Biofilm Sensors

“…The open-circuit voltage curves before and after toxicity are shown in Figure S4a, b. The second derivative of the open-circuit voltage curve was considered the terminal point by referring to the literature . Therefore, the ohmic potential loss curve was determined (Figure e).…”

“…What happens afterward has not yet been explored; the effect of the toxicant on IEG and EET has not been distinguished either. Recently, some researchers proposed a novel pulse open-circuit voltammetry (POV) method to measure the resistances from microbe–electrode interfacial processes, in which the biofilm reaction resistance ( R B,ct ) and biofilm ohmic resistance ( R B,ohm ) could be determined to indicate IEG and EET, respectively . Moreover, the constant voltage DC method based on a gap electrode could be used to characterize EET by measuring the dynamic conduction current signal. − These efforts imply that by performing the POV method and constant voltage DC measurement using a gap electrode, it is possible to determine the response of IEG and EET to the toxicant’s attack.…”

Visual Detection and Sensing of Mercury Ions and Glutathione Using Fluorescent Copper Nanoclusters

“…Contaminated samples were simulated with Hg 2+ -labeled tap water solution. A series of samples with concentration gradient (10,50,10,200, and 300 μM) were prepared by adding Hg 2+ standard solution into tap water. Then, L-Cys/CuNCs@ESM test strips were exposed to Hg 2+ spiked water samples.…”

“…The L-Cys/CuNCs@ESM composite shows a regular and significant quenching response to Hg 2+ , indicating that it can be used as an effective "on−off" intelligent sensing strip for visual detection of Hg 2+ . The possible quenching mechanism is due to the formation of a specific strong bond between the d 10 centers of Hg 2+ (5d 10 ) and Cu + (3d 10 ) in CuNCs embedded in the ESM, resulting in a highly specific affinity via metallophilic interaction. 42 Additionally, in the sensing system, due to the electrostatic and complexing interactions between Hg 2+ ions and functional groups in the ESM matrix (such as hydroxyl, carboxy, and amino group), the microenvironment of the incorporated CuNCs exhibited a significant change inevitably and the protection role of the ESM matrix in CuNCs was correspondingly weakened, resulting in the fluorescence quenching of the composite.…”

“…The luminescent components in these membranes involve fluorescent organic dyes, rare-earth complex, semiconductor quantum dots (QDs), metal nanoclusters (NCs), carbon quantum dots (CQDs), and so forth. − Metal NCs stabilize enormous metal atoms through the surface monolayer ligands and also bridged the connection between nanoparticles and molecular compounds, which is an ideal fluorescent material. Notably, as for common fluorophores such as organic dyes and semiconductor QDs, their practical application was restricted by poor photostability or toxicity issues.…”