The electrocatalytic oxidation of ethanol on membraneless sodium percarbonate fuel cell using platinum electrodes in alkalineacidic media is investigated. In this cell, ethanol is used as the fuel and sodium percarbonate is used as an oxidant for the first time in an alkaline-acidic media. Sodium percarbonate generates hydrogen peroxide in aqueous medium. At room temperature, the laminar-flow-based microfluidic membraneless fuel cell can reach a maximum power density of 18.96 mW cm −2 with a fuel mixture flow rate of 0.3 mL min −2 . The developed fuel cell features no proton exchange membrane. The simple planar structured membraneless ethanol fuel cell presents with high design flexibility and enables easy integration of the microscale fuel cell into actual microfluidic systems and portable power applications.

Red-light-emitting silver nanoclusters (AgNCs) are recently emerged as a promising nanoprobe in the field of biomedical applications, because of their attractive properties, including brightness, luminescence stability, and better biocompatibility. In this report, we have developed highly water-soluble redlight-emitting AgNCs by using N-cholyl D-penicilamine (NCPA) as a biosurfactant at above the critical micelle concentration (CMC) at room temperature. Moreover, the NCPA was initially synthesized by demonstrating the reaction between cholic acid and D-penicilamine via a simple coupling reaction strategy. The primary and secondary critical micellar concentration (CMC) of NCPA surfactant was measured using pyrene (1 × 10 −6 M) as a fluorescent probe, and the values were found to be 3.18 and 10.6 mM, respectively. Steady-state fluorescence measurements reveal that the prepared AgNCs shows the excitation and emission maxima at 365 and 672 nm, respectively, with a large Stokes shift (307 nm). The average lifetime measurements and quantum yield of the AgNCs were calculated to be 143.43 ns and 16.34%, respectively. Also, the red luminescent NCPA-templated AgNCs was synthesized in various protic and aprotic polar solvents, among which DMF and DMSO exhibit bright emission at longer wavelength as synthesized in aqueous medium. At higher concentration of AgNO 3 , bright luminescent and highly stable solid AgNCs was obtained with excitation and emission maxima at 607 and 711 nm, respectively. Furthermore, the synthesized AgNCs has been successfully utilized as a fluorescent probe for selective and sensitive detection of S 2− ions at nanomolar level in water samples, showing its potential applicability for the detection of S 2− ions in drinking, river, and tap water samples. Finally, toxicity and bioimaging studies of NCPA-templated AgNCs was demonstrated using zebrafish as in vivo model, showing no significant toxicity up to 200 μL/mL. The AgNCs-stained embryos exhibited red fluorescence with high intensity, which shows that AgNCs are stable in a living system.

Here we report an efficient and simple protocol for the preparation of N-acetylcysteine conjugated cholic acid (ACyCA) by adopting thiol-yne click chemistry approach. The synthesized ACyCA amphiphiles showed primary and secondary critical micellar concentration (CMC) at 3.6 and 11.05 mM. The prepared ACyCA was used as a soft template for the preparation of gold (Au) and silver (Ag) nanoparticles (NPs) under sun light exposure. The optical and morphological properties of NPs were studied by UV-visible, DLS, zeta potential and HR-TEM techniques. The synthesized NPs having monodispersed spherical shaped and anisotropic nature with an average size of ∼ 10.5 nm and ∼ 45.8 nm for Au and Ag NPs, respectively. The catalytic activity of the prepared NPs was evaluated for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) as a model reaction and the apparent rate constant (k app ) was found to be 3.27 × 10 À 4 s À 1 and 15.6 × 10 À 4 s À 1 for Au and Ag NPs respectively. Also, Ag and Au NPs were screened for antimicrobial activity against five human pathogens. Among these, AgNPs showed maximum zone of inhibition (ZOI) 23 mm for Staphylococcus aureus when compared to AuNPs, and the minimum inhibitory concentration of AgNPs was found to be 64 μg/mL for S. aureus. From the haemocompatibility studies, the AgNPs showed more compatibility for the human blood cells as compared to AuNPs. Multiphoton confocal fluorescent microscopic observation of bacterial cells treated with AgNPs showed 45 to 50 % of dead cells.

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A microfluidic fuel cell has been fabricated using formic acid in an alkaline media as the fuel and sodium percarbonate in acidic media as the oxidant. Various operating conditions and different cell dimensions were applied to evaluate the fuel cell performance. The laminar flow-based membraneless fuel cell was found to reach a maximum power density of 23.60 mW cm-2 using 1.50 M HCOOH in 3 M NaOH solution as the fuel and 0.15 M percarbonate in 1.50 M H2SO4 solution as the oxidant at room temperature. The fuel cell system has no proton exchange membrane. This simple membraneless fuel cell with a planar structure has a high design flexibility, which enables its easy integration into actual microfluidic systems and miniature power applications.