Next generation of chemistry and biochemistry conference posters: Animation, augmented reality, visitor statistics, and visitors' attention.

Every branch of science needs visitors' attention during the poster presentation session at conferences, symposiums, seminars, etc. In particular, participants in the chemistry and biochemistry conference need more visual tools to explain their research work in detail. Presence of smartphones and the ability of 2D barcodes will allow chemical reactions or processes to be shown in the form of a movie, animation or augmented reality (AR). Therefore, the next generation of posters will be more interested in this view. Here, the ability of 2D barcodes or QR codes to help researchers to catch more attention in their research work was presented during a poster presentation session. In this way, the visitors showed positive attitudes to the applicability of such tools. Also, some information including the number of poster visitors and interesting topics in the conference can be collected easily which is useful for the scientific and organizing committee of conferences. As a result, biochemistry conference posters can be presented in new ways, based on animation images or video, to capture the attention of viewers and deepen their understanding of poster concepts.

Carbon dots on V2O5 nanowires are a viable peroxidase mimic for colorimetric determination of hydrogen peroxide and glucose.

A nanocomposite was hydrothermally prepared from C-dots and V2O5 nanowires, and characterized by TEM, FTIR and XRD. Due to the synergistic effects between C-dots and V2O5 nanowires, the nanocomposite is found to possess peroxidase-mimicking activity. This finding was exploited to design colorimetric methods for determination of H2O2 and glucose (via glucose oxidase) by using of 3,3',5,5'-tetramethylbenzidine (TMB) as the chromogenic substrate. The C-dot/V2O5 nanocomposite catalyzes hydrogen peroxide to oxidize TMB and the resultant product, i.e., TMB* produces a blue color in the solution. Also for glucose determination, at first glucose reacts with dissolved oxygen in the presence of glucose oxidase and generates H2O2. Then, produced H2O2 was monitored by the C-dot/V2O5 nanozyme in the presence of TMB. Intensity of the blue color in the solution at wavelength of 650 nm is an indication of H2O2 or glucose concentration. The response to H2O2 is linear in the 0.5-520 µM concentration ranges, and that for glucose from 0.7 µM to 300 µM. Graphical abstract Schematic presentation of peroxidase mimicking activity of C-dot/V2O5 nanocomposite and its application as sensitive colorimetric H2O2/glucose assay by using of 3,3',5,5'-tetramethylbenzidine (TMB) as chromogenic substrate to induce a typical blue color reaction.

Quantitative structure-retardation factor relationship of protein amino acids in different solvent mixtures for normal-phase thin-layer chromatography.

A quantitative predictive/descriptive model was proposed for the retardation factors of protein amino acids in normal-phase thin-layer chromatography. The experimental retardation factors of 126 chromatographic mixtures (21 protein amino acids in different mobile phases) were used as the independent variable. The matrix of dependent variables of the model was built using structural descriptors of amino acids and empirical parameters of solvents of the applied mobile phases. After variable selection, a five-parametr model was proposed for the retardation factor of amino acids, which covered about 84 and 77% variance of data in training and cross-validation, respectively. The correlation coefficient of the external test set was 0.80, which shows the prediction potential of proposed model as well as its good applicability domain that was checked using a standardized residual-leverage plot.

Chemometrics assisted resolving of net faradaic current contribution from total current in potential step and staircase cyclic voltammetry.

Total current in the electroanalytical data is assumed to be consisting of three main constituents: faradaic current, step charging current and induced charging current. Both charging currents can cause an interfering effect on precise determination of faradaic currents, and hence insert direct effects on sensitivity and detection limit of the electroanalytical techniques. Despite the widespread techniques introduced until now, the extraction of the net faradaic current from total current still remains a challenge. In this work, by using multivariate curve resolution-alternating least square (MCR-ALS) as a powerful curve resolution-based chemometrics method, a straightforward method has been introduced for resolving faradaic current from the two types of charging currents (step charging current and induced charging current) in single potential step and staircase cyclic voltammetric methods. By simultaneous analyses of the current data matrices for different electrochemical systems, the three sources of current were successfully identified and their contributions in the total signal were easily calculated. Also, in this manner, the cell time constant can be obtained easily. Contrary to the previously reported methods, the present method does not need any pre-determined mathematical method; particularly there is no need to know the cell time constant.