A robust computational investigation on C₆₀ fullerene nanostructure as a novel sensor to detect SCNˉ

This study explored on the adsorption properties and electronic structure of SCNˉ via density functional theory analysis on the exterior surfaces of C₆₀ and CNTs using B3LYP functional and 6-31G** standard basis set. Then adsorption of SCNˉ through nitrogen atom on the C60 fullerene is electrostatic (₋48.02 kJ molˉ1) in comparison with the C₅₉Al fullerene that shows covalently attached to fullerene surface (₋389.10 kJ mol̄ˉ1). Our calculations demonstrate that the SCNˉ adsorption on the pristine and Al-doped single-walled CNTs are ₋173.13 and ₋334.43 kJ molˉ1, indicating that the SCNˉ can be chemically bonded on the surface of Al-doped CNTs. Moreover, the adsorption of SCNˉ on the C₆₀ surface is weaker in comparison with C₅₉B, C₅₉Al, and C₅₉Ga systems but its electronic sensitivity improved in comparison with those of C₅₉B, C₅₉Al, and C₅₉Ga fullerenes. The evaluation of adsorption energy, energy gap, and dipole moment demonstrates that the pure fullerene can be exploited in the design practice as an SCNˉ sensor and C₅₉Al can be used for SCNˉ removal application

The internal/external frame of reference of academic self-concept: Extension to a foreign language and the role of language of instruction

The internal/external frame of reference (I/E) model (Marsh, 1986) posits that the effects of contrasting math and verbal domains of achievement are positive for matching academic self-concepts (ASCs) but negative for nonmatching ASCs (i.e., math achievement on verbal ASC; verbal achievement on math ASC). We extend the classic I/E model by contrasting the math domain with 2 verbal domains (Chinese, native language; English, foreign language) in combination with language of instruction (English or Chinese) for a sample of 1,950 Hong Kong Year 7 students. Consistent with predictions based on the Marsh and Shavelson (1985) ASC model and our extension of the I/E model, we found that native and foreign languages were not contrasted with each other in the formation of ASCs. However, achievement in both verbal domains negatively predicted math ASC, while math achievement was also negatively predicted by ASCs in both verbal domains. Support for the predictions was similar for students taught in English and Chinese languages of instruction

Probe–Integrated Electrochemical Sensing Platform for Measuring Trace levels of parathion pesticides residues in water using Au- nanoparticles anchored Nafion nano composite modified glassy carbon electrode

Nanomaterial represents a principal driver to the adoption of electrochemical sensors for pesticides residues in water. Thus, the current strategy reports facile and highly sensitive electrochemical probe for monitoring parathion residues in water. The probe was based upon the use of Au nanoparticles (AuNPs) functionalized Nafion nanocomposites modified glassy carbon electrode (Au NPs/Nafion/GCE). The surface morphology, effective surface area and electrocatalytic performance of the Au NPs/Nafion/GCE were recorded and assigned using a scanning electron microscopy (SEM), cyclic voltammetry (CV) and electronic spectra. A straightforward protocol based upon combination of Au NPs/Nafion/GCE and square wave- adsorptive cathodic stripping voltammetry at pH 7.0 was established for parathion detection. The probe displayed two linear responses between the catholic peak current (ip,c) at 0.8 V versus parathion concentrations over the ranges from 1.07 × 10 6 - 1.07 × 10 5 and 1.99 × 10 9 - 9.0 × 10 7 M with limits of detection (LOD) and quantification (LOQ) of 6.06 × 10 10 M and 2.0 × 10 9 M, respectively. The probe exhibited excellent reproducibility, repeatability with RSD of ± 0.5% (n = 5) at 8.0 × 10 7 M parathion. The probe was applied for parathion detection in water and validated by HPLC. The experimental Student texp and Fexp values were less than the tabulated ttab (2.78) and Ftab (6.39) at 95% probability