Functionalized fluorescent nanomaterials for sensing pollutants in the environment: A critical review

Quantitation of environmental pollutants has gained momentum due to its widespread requirement in the fields of clinical research, occupational hygiene, public health, and societal welfare. The use of functionalized fluorescent nanomaterials (FFNMs: e.g., metal nanoparticles, semiconductor quantum dots, carbon dots, nanotubes, and nanocrystals) has opened a new avenue for creating simple, selective, and non-invasive real-time analysis, as they can satisfy the growing demand for rapid and cost-effective quantitation. Here, we discuss novel strategies for the qualitative and quantitative analysis of a variety of organic and inorganic environmental pollutants by detecting changes in photo-physical or optical properties (e.g., fluorescence, absorbance, and color) of FFNMs used as probes. Particularly, we emphasize potential approaches for the synthesis and characterization of FFNMs and their underlying interactions with environmental pollutants. The simplification of design and enhancement of specificity towards target analytes should be pursued further to upgrade their real-world applicability in diverse fields

Spectroscopic analysis on the binding interaction of biologically active pyrimidine derivative with bovine serum albumin

A biologically active antibacterial reagent, 2–amino-6-hydroxy–4–(4-N, N-dimethylaminophenyl)-pyrimidine-5-carbonitrile (AHDMAPPC), was synthesized. It was employed to investigate the binding interaction with the bovine serum albumin (BSA) in detail using different spectroscopic methods. It exhibited antibacterial activity against Escherichia coli and Staphylococcus aureus which are common food poisoning bacteria. The experimental results showed that the fluorescence quenching of model carrier protein BSA by AHDMAPPC was due to static quenching. The site binding constants and number of binding sites (n≈1) were determined at three different temperatures based on fluorescence quenching results. The thermodynamic parameters, enthalpy change (ΔH), free energy (ΔG) and entropy change (ΔS) for the reaction were calculated to be 15.15 kJ/mol, –36.11 kJ/mol and 51.26 J/mol K according to van't Hoff equation, respectively. The results indicated that the reaction was an endothermic and spontaneous process, and hydrophobic interactions played a major role in the binding between drug and BSA. The distance between donor and acceptor is 2.79 nm according to Förster's theory. The alterations of the BSA secondary structure in the presence of AHDMAPPC were confirmed by UV–visible, synchronous fluorescence, circular dichroism (CD) and three-dimensional fluorescence spectra. All these results indicated that AHDMAPPC can bind to BSA and be effectively transported and eliminated in the body. It can be a useful guideline for further drug design

Comparative evaluation and Immunohistochemical expression of Syndecan-1 in Ameloblastoma and Dentigerous cyst.

Background: Syndecans are type-1 heparan sulphate proteoglycans which play significant role in cell-cell and cell-extracellular matrix interaction. Syndecans are involved in tooth development and differentiation of mesenchymal cells. Amongst odontogenic lesions, ameloblastomas and dentigerous cysts are routinely encountered lesions with difference in treatment modality based on its aggressiveness. The objective of the present research was to study and compare immunohistochemical expression of syndecan-1 in ameloblastoma and dentigerous cyst. Method:  40 retrospectively diagnosed cases of ameloblastomas and dentigerous cysts were immunohistochemically stained against syndecan-1. The intensity of immunostaining and percentage of positive cells was assessed by three independent blind observers. Weighted kappa test was used to find out inter-observer reliability. Comparative evaluation of syndecan-1 expression between the two lesions was done using student t-test. Results:  There was statistically significant difference between the mean of score for intensity, mean of score for percentage of positive cells and total mean score of syndecan-1 between ameloblastoma and dentigerous cyst. Conclusion: Syndecan-1 may be involved in aetiopathogenesis of odontogenic lesions like ameloblastoma and dentigerous cyst. Also, weak expression in ameloblastoma indicates that tumor invasion and aggressiveness is related to cell adhesion molecule like syndecan-1

Selective synthesis of 10,11-dihydrochromeno[4,3-<i>b</i>]chromene-6,8(7<i>H</i>,9<i>H</i>)-dione using copper oxide nanoparticles for potential inhibitors of β-ketoacyl-[acyl-carrier-protein] synthase III of <i>Mycobacterium tuberculosis</i>

1151-1159A simple and selective synthesis of 10,11-dihydrochromeno[4,3-b]chromene-6,8(7H,9H)-dione derivatives has been investigated by multicomponent reaction of aromatic aldehydes, 4-hydroxycoumarin and dimedone using copper oxide nanoparticles. All the synthesised coumarin derivatives have been screened for anti-tubercular activity. The virtual analysis of the synthesised derivatives have also been carried out against β-ketoacyl-[acyl-carrier-protein] synthase III. The inhibition of the β-ketoacyl-[acyl-carrier-protein] synthase III is confirmed from the docking study. The experimental results have shown that the compound 10,10-dimethyl-7-(3-nitrophenyl)-10,11-dihydrochromeno[4,3-b]chromene-6,8(7H,9H)dione (MIC 6.25 μg/mL) is a good anti-tubercular agent and as good as standard streptomycin drug based on minimum inhibitory concentration

Surface plasmon resonance based colorimetric probe for vitamin B1 detection: Applications to bio-fluid analysis

This study reports simple analytical approach for thiamine (Vitamin B1) detection based on induced aggregation and alternation in colorimetric properties of gold nanoparticles (AuNPs), which was synthesized through citrate reduction approach. Furthermore, the citrate capped AuNPs are characterized by various analysing tools. The addition of thiamine persuades the aggregation of citrate-AuNPs and further leading to red to blue colour transition with decrease in absorbance intensity. The proposed method achieves good linearity with a correlation coefficient of 0.9843. By using our proposed strategy, thiamine was detected by unassisted vision as well as absorption spectroscopy. Under the most favorable condition method achieves good linear relationship between concentration range 0.01–0.8 μg mL−1 with limit of detection of 0.0067 μg mL−1. Under the premium condition, the method offers excellent selectivity towards thiamine detection in presence of different interfering species. Further practical applicability of the method was checked by using blood serum and urine sample via standard addition method. The obtained recoveries were acceptable in the range of 98.70–102.97% for added thiamine concentration. Thus, the proposed method may emerge as a target specific and highly sensitive tool towards thiamine detection