Using bacteria-templated polymerization, a novel bacteria-imprinted polymer (BIP) was fabricated for bacterial recognition. Charge distribution on bacterial outer surfaces was encoded into charge heterogeneous polymeric interfaces on BIPs as chemical imprints. Through integrating with a microfluidic chip, the synthesized BIPs exhibited excellent performance for fast bacterial recognition.

Microbial three-electrode cells (M3Cs) have been widely used as a promising platform for developing biosensors and studying electrochemically active bacteria (EAB). Compared to conventional microbial two-electrode cells (e.g. microbial fuel cells and microbial electrolysis cells), M3Cs can offer more stable and better defined electrochemical environments for various research purposes. This work focused on developing a microliter scale microfluidic M3C, which had unique advantages over bench scale M3Cs. In this microfluidic M3C with a built-in three electrode system, laminar flow was exploited to separate the reference electrode from the working and the counter electrodes. Using laminar flow made it possible to integrate the M3C with a microliter scale microfluidic chip and maintain a stable Ag/AgCl electrode potential. With the help of the integrated three-electrode setup, the working electrode potential of the microfluidic M3C was able to be accurately controlled and thus a well-defined electrochemical environment was provided to Geobacter sulfurreducens to respire on the electrode. During 30 days operation, the reference electrode potential was stable, which guaranteed the accurate control of the working electrode potential. By taking advantage of the microliter scale and a short hydraulic retention time (HRT), fast responses to ferric citrate and formaldehyde with good reproducibility were achieved. Furthermore, a linear relationship between the output signals (peak area) and chemicals concentrations was obtained. The microfluidic M3C developed in this work will provide researchers in related areas a versatile platform for biosensor and EAB study.

•A polypropylene membrane based solid electrolyte was developed for CO2 reduction.•The membrane was developed by deposition of bio-inspired polyphenolic coatings.•High CO production rate and the Faradaic efficiency were achieved.•The novel composite SPE may have great potential in industrial application.A novel solid polymer electrolyte was developed by co-deposition of catechol (CCh) and polyethyleneimine (PEI) on a polypropylene membrane for electrochemical reduction of CO2 (ERC) in gas phase. ERC performance was both investigated in a gas-gas mode and a gas-liquid mode. The maximum CO production rate was 121 μmol/h and the faradaic efficiency was 51% in the gas-liquid mode, which were much higher than those obtained with AM-7001 under the same condition. The high loading rate of quaternary ammonium ions on the membrane and the large surface area provided by the porous nano-structure of the membrane contribute to the high ERC efficiency. Furthermore, the cost of the CCh/PEI-Q membrane was much lower than commercial Nafion membranes, endowing this novel composite SPE with great potential in industrial application.

•a non-invasive electrochemically active bacterial biofilm growth monitoring method was developed.•Using a Pt microelectrode for in vivo measuring the bacterial biofilm thickness for the first time.•Results of this approach is accurate by CLSM validation.•This approach has been used for monitoring environmental factors influence on Shewanella oneidensis MR-1 biofilm formation.Much attention has been focused on electrochemically active bacteria (EAB) in the application of bioelectrochemical systems (BESs). Studying the EAB biofilm growth mechanism as well as electron transfer mechanism provides a route to upgrade BES performance. But an effective bacterial growth monitoring method on the biofilm scale is still absent in this field. In this work, electrode-attached bacterial biofilms formed by Shewanella oneidensis MR-1 were dynamically monitored through a microelectrode method. For S. oneidensis MR-1, a respiratory electron transport chain is associated with the secretion of riboflavin, severing as the cofactor to the outer membrane c-type cytochromes. The biofilm growth was monitored through adopting riboflavin as an electrochemical probe during the approach of the microelectrode to the biofilm external surface. This method allows in vivo and in situ biofilm monitoring at different growth stages without destructive manipulation. Furthermore, the biofilm growth monitoring results have been proved to be relatively accurate through observation under confocal laser scanning microscopy. We further applied this method to investigate the effects of four environmental factors (the concentrations of dissolved oxygen, sodium lactate, riboflavin as well as the electrode potential) on S. oneidensis MR-1 biofilm development.

An optical signal was successfully used to reversibly switch the ON/OFF states of a microbial fuel cell via an optical switching system consisting of a functionalized electrode and a photoacid. Using this switching system as the controlling component achieved the effective, fast and reliable control of a microbial fuel cell.

Kinetics of iron(II)- and manganese(II)-catalyzed oxidation of S(IV) in seawater were studied here to provide theoretical support for the flue gas desulfurization process (SFGD). Experiments were carried out with artificial seawater and acetic buffer. Results indicated that the reaction order with respect to dissolved oxygen is zero. However, the reaction order with respect to S(IV) is variable: second-order under uncatalyzed condition (4.0 ≤ pH ≤ 7.0); first-order under Fe(II)-catalyzed oxidation (2.5 ≤ pH ≤ 3.5); first-order (4.0 ≤ pH ≤ 5.0) and second-order (5.5 ≤ pH ≤ 5.9) under Mn(II)-catalyzed oxidation. The different S(IV) dependence could be attributed to different metal speciation at different pH values. Also, acetate is found to have significant inhibition effect on Mn(II)-catalyzed oxidation in high ion strength solution. The strong catalytic effect of Fe(II) and Mn(II) ions on S(IV) oxidation could lead to new ideas for the design of SFGD systems.

In this work, three 4-dimethylaminopyridinium-based ionic liquids (ILs), N-ethyl-4-dimethylaminopyridinium dicyanamide ([C24DMAPy][N(CN)2]), N-butyl-4-dimethylaminopyridinium dicyanamide ([C44DMAPy][N(CN)2]) and N-hexyl-4-dimethylaminopyridinium dicyanamide ([C64DMAPy][N(CN)2]), were synthesized and then demonstrated to be efficient for aromatic sulfur compounds extraction from fuels. The mutual solubility evaluating results indicated that 4-dimethylaminopyridinium-based ILs hardly dissolved in the fuels, while the solubility of 97# gasoline in ILs varies from 7.0 wt % for [C24DMAPy][N(CN)2] to 12.4 wt % for [C64DMAPy][N(CN)2] and the solubility of 0# diesel in ILs varies from 6.7 wt % for [C24DMAPy][N(CN)2] to 9.7 wt % for [C64DMAPy][N(CN)2]. Also, the sulfur partition coefficient was evaluated. In the case of model gasoline, the thiophene (TS) partition coefficient in model gasoline varies from 0.885 for [C24DMAPy][N(CN)2] to 1.218 for [C64DMAPy][N(CN)2]. In the case of model diesel, 4-dimethylaminopyridinium-based ILs exhibit a relatively higher sulfur partition coefficient, compared to alkyl modified pyridinium-based ILs. 1H NMR results confirmed that the high aromatic π-electron density of the dimethylaminopyridinium cation was the main reason for the good extraction performance. 1H NMR results also confirmed the KN sequence for each IL ([C24DMAPy][N(CN)2] < [C44DMAPy][N(CN)2] < [C64DMAPy][N(CN)2]) is mainly due to the sulfur compounds and ILs structures. Furthermore, the extractive selectivity results indicated a more preferable extraction of TS than toluene with 4-dimethylaminopyridinium-based ILs. To have a better evaluation of the overall sulfur extraction performance, the three 4-dimethylaminopyridinium-based ILs were compared to other typical ILs (e.g., pyridinium-based ILs and imidazolium-based ILs), which suggested our synthesized 4-dimethylaminopyridinium-based ILs exhibited good balance between mutual solubility and the sulfur partition coefficient. ILs after use were regenerated by a water dilution process. Based on these results, 4-dimethylaminopyridinium-based ILs can be used as potential extractants for EDS processes.

Using bacteria-templated polymerization, a novel bacteria-imprinted polymer (BIP) was fabricated for bacterial recognition. Charge distribution on bacterial outer surfaces was encoded into charge heterogeneous polymeric interfaces on BIPs as chemical imprints. Through integrating with a microfluidic chip, the synthesized BIPs exhibited excellent performance for fast bacterial recognition.