Synthesis and structural elucidation of a unique turn-off fluorescent sensor based on oxo-bridged tin (IV) cluster for selective detection of dopamine in biological fluids.

An oxo-bridged Sn (IV) Cluster, (TOC) was synthesized and fully characterized by FT-IR, UV-vis, 1H NMR, 119Sn NMR, Mass spectrometry and single crystal X-ray diffraction studies. The single-crystal X-ray analysis revealed that the crystal crystallizes in the monoclinic crystal system possessing the P 21/c space group and exhibited a distorted trigonal bipyramidal geometry. The TOC exhibited a unique turn-off fluorescence response for the selective detection of dopamine (DA) over other analytes. The stoichiometry between the TOC and DA was calculated using Job's plot. The value of the detection limit was found to be 1.33 µM. The Hirshfeld surface analysis was carried out on the crystal structure to investigate the H-H, Cl-H, Cl-Cl, Sn-Cl and Cl-C interaction studies in the molecule. Density Functional Theory (DFT) studies further supported the sensing mechanism, which closely agreed with the experimental results. Furthermore, the TOC chemosensor was used to detect DA in human blood plasma, and molecular docking studies validated the interaction between the chemosensor and protein. Confocal fluorescence imaging studies were carried out and validated TOC sensing ability for DA in human blood plasma.

Is stock market development sensitive to macroeconomic indicators? A fresh evidence using ARDL bounds testing approach.

Over the past decades, emerging stock markets have started to significantly contribute to economic growth through mobilizing long-term capital by pooling funds, facilitating savings and investments into profitable projects and improving corporate governance structure. A plethora of empirical studies is devoted to investigate the determinants of different capital markets but due to highly controversial and inconclusive findings about macroeconomic determinants, this study contributes to the body of existing literature by empirically investigating the macroeconomic forces that drive the stock market development of Pakistan from 1980 to 2019. By applying Ng-Perron and Zivot-Andrews unit root tests (to determine the integrating orders of variables) and Autoregressive Distributed Lag (ARDL) bounds testing approach, our results confirm cointegration among variables and exhibit the significant positive impact of economic growth and banking sector development on stock market development and negative affect of inflation, foreign direct investment and trade openness on it in long run. At the same time, the short run results show a significant relationship of economic growth, inflation and foreign direct investment with stock market development. Our study has some important policy implications.

The IFRS adoption, accounting quality, and banking performance: An evaluation of susceptibilities and financial stability in developing economies.

International Financial Reporting Standards (IFRS) 's adoption increased attention to International Accounting Standard Regulations worldwide. It has opened the door for empirical analysis having different perceptions of mandatory IFRS adoption. This paper's main objective is to examine the impact of accounting quality and IFRS adoption on Pakistan's banking sector efficiency. We have employed the Malmquist productivity index, Roychowdhury's Earnings Management, and modified learner index to conduct the empirical analysis. The results mean how much banking sector efficiency is affected by accounting quality and IFRS adoption. The results demonstrate that the banking sector efficiency significantly increases through accounting quality and IFRS. Furthermore, it can be seen that the foreign banks' efficiency in Pakistan is less than other banks compared to public or private banks. Additionally, more earnings timeliness has been noted in large banks than medium and small banks in Pakistan. Preferably, the practice of quality accounting relies on disclosed information through financial statements. In contrast, the organizations may evade the losses once the information quality is precise and appropriate. The study provides valuable information to managers and other stakeholders.

"Turn-on" benzophenone based fluorescence and colorimetric sensor for the selective detection of Fe2+ in aqueous media: Validation of sensing mechanism by spectroscopic and computational studies.

A diaminobenzophenone Schiff base derived probe 1, was synthesized and structure elucidation was carried out by spectroscopic studies viz., FT-IR, UV-vis, 1H, and 13C NMR and mass spectrometry. The sensing phenomenon with different metal ions (Cr3+, Mn2+, Fe2+, Fe3+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+) was investigated by employing absorption and fluorescence titrations, which demonstrated that probe 1 exhibited selective fluorescent sensing behavior towards Fe2+ ion among various other metal ions. The porobes selceteclivity towards Fe2+ was also examined by colorimetric assay which revealed a change in the color from light yellow to brown upon addition of Fe2+ ion. A remarkable increase in the fluorescence intensity of probe 1 was observed towards Fe2+ ion, which was found to be associated with the inhibition of photoinduced electron-transfer (PET) and CN isomerization processes, respectively. The chemosensor exhibited an association constant value of 6.173 × 107 M-2 as determined by using non-linear least square fit data. Job's plot calculated the binding stoichiometry, and the sensing phenomenon of Fe2+ towards the probe was further supported by Density Functional Theory (DFT) calculations and 1H NMR studies. The detection limit of probe 1 was found to be 0.0363 µM, which is below the permissible limits according to the WHO guideline (5 µM) for Fe2+ ions in the drinking water. Furthermore, the practical application of probe 1 was studied by analyzing the content of Fe2+ in different water samples.