Selective capturing of phenolic derivative by a binary metal oxide microcubes for its detection

A Review on Flexible Electrochemical Biosensors to Monitor Alcohol in Sweat

The continued focus on improving the quality of human life has encouraged the development of increasingly efficient, durable, and cost-effective products in healthcare. Over the last decade, there has been substantial development in the field of technical and interactive textiles that combine expertise in electronics, biology, chemistry, and physics. Most recently, the creation of textile biosensors capable of quantifying biometric data in biological fluids is being studied, to detect a specific disease or the physical condition of an individual. The ultimate goal is to provide access to medical diagnosis anytime and anywhere. Presently, alcohol is considered the most commonly used addictive substance worldwide, being one of the main causes of death in road accidents. Thus, it is important to think of solutions capable of minimizing this public health problem. Alcohol biosensors constitute an excellent tool to aid at improving road safety. Hence, this review explores concepts about alcohol biomarkers, the composition of human sweat and the correlation between alcohol and blood. Different components and requirements of a biosensor are reviewed, along with the electrochemical techniques to evaluate its performance, in addition to construction techniques of textile-based biosensors. Special attention is given to the determination of biomarkers that must be low cost and fast, so the use of biomimetic materials to recognize and detect the target analyte is turning into an attractive option to improve electrochemical behavior.

A Ready-to-Use Metal-Supported Bilayer Lipid Membrane Biosensor for the Detection of Phenol in Water

This work presents a novel metal-supported bilayer lipid membrane (BLM) biosensor built on tyrosinase to quantitate phenol. The detection strategy is based on the enzyme-analyte initial association and not the commonly adopted monitoring of the redox cascade reactions; such an approach has not been proposed in the literature to date and offers many advantages for environmental monitoring with regard to sensitivity, selectivity, reliability and assay simplicity. The phenol sensor developed herein showed good analytical and operational characteristics: the detection limit (signal-to-noise ratio = 3) was 1.24 pg/mL and the sensitivity was 33.45 nA per pg/mL phenol concentration. The shelf life of the tyrosinase sensor was 12 h and the lifetime (in consecutive assays) was 8 h. The sensor was reversible with bathing at pH 8.5 and could be used for eight assay runs in consecutive assays. The validation in real water samples showed that the sensor could reliably detect 2.5 ppb phenol in tap and river water and 6.1 ppb phenol in lake water, without sample pretreatment. The prospects and applicability of the proposed biosensor and the underlying technology are also discussed.

Sensitive and selective determination of triclosan using visual spectroscopy

Triclosan is a commonly used biocide effective against bacterial and fungal infections. However, its overuse in pharmaceutical and personal care products has resulted in its abundance in the natural environment. The detection of triclosan by visual spectroscopy can be carried out using the azo-coupling reaction of diazonium complexes. However, the reaction is also common to other phenolic compounds and aromatic amines, posing significant challenge. In this work, we investigate the azo-coupling reaction of triclosan and several commonly occurring analogous compounds to develop an improved spectroscopic method for the selective determination of triclosan without interference. We find that the azo-coupling reaction between the diazotized derivative and the phenolic compounds is highly dependent on the pH of the reaction media. At pH 7.2, the absorbance of the azo dye product of triclosan shows a peak at 452 nm which has minimal interference from other phenolic azo-dye products with the exception of naphthol. Naphthol shows an interference corresponding to 58% of the analytical signal of equimolar triclosan concentration. To overcome this, we develop an analytical model for the simultaneous determination of triclosan and naphthol from mixed solutions of the compounds. A linear calibration plot from 1.7 to 34 µM was obtained for both triclosan and naphthol with limit-of-detection (LOD) of 0.62 µM and 1.03 µM respectively. The developed protocol was tested for the analysis of water samples collected from various environmental sources spiked with different concentrations of triclosan and naphthol. The samples were enriched by solid-phase-extraction which allowed a 50-fold enhancement in detection of triclosan. The average relative recovery of triclosan in real samples was found to be 98.6% .

The influence of phenolic environmental estrogen on the transcriptome of uterine leiomyoma cells: A whole transcriptome profiling-based analysis

OBJECTIVE

The study aimed to recognize potential molecular targets and signal pathways whereby phenolic environmental estrogen promotes the proliferation of uterine leiomyoma cells.

METHODS

Primary cultured cell lines of uterine leiomyoma were treated with 0.1% DMSO, 10.0μmol/L Bisphenol A (BPA), and 32.0μmol/L Nonylphenol (NP) for 48 h before RNA-seq was performed. Those genes affected by BPA and NP were identified. Then, Gene Ontology (GO) enrichment, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment, and Protein-protein Interaction (PPI) analysis were performed. Quantitative real-time polymerase chain reaction (q-PCR) and western blot were used to verify the differentially expressed gene and protein.

RESULTS

Compared to with the control group, 739 differentially expressed genes were identified in both the BPA group and the NP group. GO enrichment analysis showed that the most enriched GO terms were connective tissue development and G1/S transition of mitotic cell cycle, and extracellular matrix. The results of KEGG enrichment analysis showed that differentially expressed mRNA were enriched mainly in three primary pathways, including environmental information processing, human diseases, and cellular processes. The cell cycle, PI3K-Akt signaling pathway are significantly enriched. The q-PCR and western blot verified the cell cycle associated genes and proteins were upregulated in both BPA group and NP group. Both BPA and NP activated the PI3K-AKT signaling pathway.

CONCLUSION

Phenolic environmental estrogens may promote the proliferation and cell cycle progression of uterine leiomyoma cells through rapid non-genomic ER signaling, which leads to disordered cell cycle regulation and accelerates the transition of the cell cycle from G0/G1 phase to S phase. In addition, as an external stimulant, phenolic estrogen promotes the upregulation of inflammatory factors in uterine leiomyomas.

Synthesis of hierarchically structured T-ZnO-rGO-PEI composite and their catalytic removal of colour and colourless phenolic compounds

Phenolic compounds bisphenol A (BPA) and 4-nitrophenol (4-NP) are the prime water contaminants. As reported, these compounds are some of the highly hazardous ones to the human and living species. In this study, T-ZnO-rGO-PEI composite was synthesized employing hydrothermal method and the obtained composite samples were systematically characterized by FTIR, XPS, FE-SEM and HR-TEM studies. The FTIR, XPS analysis confirmed the successful surface modification of T-ZnO-rGO-PEI composite. The FE-SEM morphology confirmed the formation of ZnO (arm length about 2.5 μm) tetrapod structured in synthesized T-ZnO-rGO-PEI composite. The thickness of formed ZnO arm (0.44 μm) was increased after the polymer coating which confirmed the successful surface modification by PEI polymer. The HR-TEM images confirm the uniform coating of PEI polymer on T-ZnO-rGO surface. The catalytic activity and adsorption capacity of the synthesized T-ZnO-rGO-PEI composite was successfully explored using 4-nitrophenol and bisphenol-A as model pollutants .T-ZnO-rGO-PEI composite and found that 4-NP reduction reaction was completed within 10 min with the rate of 0.224 min^-1. The BPA adsorption over T-ZnO-rGO-PEI exhibited high adsorption rate of 0.0210 min^-1. In addition, the detailed 4-NP reduction and BPA adsorption mechanism was demonstrated. Hence the synthesized T-ZnO-rGO-PEI composite is a promising catalyst for the removal of micropollutants in aqueous medium.

Fabrication of selective and sensitive chemical sensor probe based on ternary nano-formulated CuO/MnO2/Gd2O3 spikes by hydrothermal approach

In this approach, thin spikes (NSs) of ternary nano-formulated mixed CuO/MnO₂/Gd₂O₃ were synthesized by the hydrothermal approach for efficient detection of 3-methoxyphenyl hydrazine (3-MPHyd) chemical from various environmental samples. The NSs were systematically characterized by using XPS, EDS, TEM, FTIR, UV/vis, and XRD. The fabricated NSs onto the glassy carbon electrode (GCE) was successfully applied for the selective and sensitive detection of 3-MPHyd in the phosphate buffer system (PBS), which displayed the highest sensitivity, good selectivity with ultra-trace detection limit, high stability, good reproducibility, and quick response time. The real environmental samples were tested for validation from stand point of the ternary doped nanomaterials for sensing in the practical applications using by electrochemical method.

Textile sensors platform for the selective and simultaneous detection of chloride ion and pH in sweat

The development of wearable sensors, in particular fully-textile ones, is one of the most interesting open challenges in bioelectronics. Several and significant steps forward have been taken in the last decade in order to achieve a compact, lightweight, cost-effective, and easy to wear platform for healthcare and sport activities real-time monitoring. We have developed a fully textile, multi-thread biosensing platform that can detect different bioanalytes simultaneously without interference, and, as an example, we propose it for testing chloride ions (Cl^-) concentration and pH level. The textile sensors are simple threads, based on natural and synthetic fibers, coated with the conducting polymer poly(3,4-ethylenedioxythiophene):poly(styrene-sulfonate) (PEDOT:PSS) and properly functionalized with either a nano-composite material or a chemical sensitive dye to obtain Cl^- and pH selective sensing functionality, respectively. The single-thread sensors show excellent sensitivity, reproducibility, selectivity, long term stability and the ability to work with small volumes of solution. The performance of the developed textile devices is demonstrated both in buffer solution and in artificial human perspiration to perform on-demand and point-of-care epidermal fluids analysis. The possibility to easily knit or sew the thread sensors into fabrics opens up a new vision for a textile wearable multi-sensing platform achievable in the near future.

Facile SrO nanorods: an efficient and alternate detection approach for the selective removal of 4-aminophenol towards environmental safety

In this approach, it is introduced a new route to fabricate a reliable and reproducible wet-chemically prepared SrO NRs fabricated glassy carbon electrode sensor probe by electrochemical method for the detection of phenolic derivatives for the safety of environmental and healthcare fields in broad scales.

Detection of 3,4-diaminotoluene based on Sr0.3Pb0.7TiO3/CoFe2O4 core/shell nanocomposite via an electrochemical approach

We reported a scalable sol–gel method for the preparation of Sr_0.3Pb_0.7TiO₃/CoFe₂O₄ core–shell magnetic nanocomposite with a finely controlled shell and evaluated its efficiency as an electrochemical sensor for the selective detection of 3,4-diaminotoluene.

Assessment of environmentally unsafe pollutants using facile wet-chemically prepared CeO2–ZrO2 nanocomposites by the electrochemical approach

Selective and sensitive 4-methoxyphenol chemical sensor was developed with a co-doped CeO₂–ZrO₂ nanocomposite modified glassy carbon electrode as a sensor probe by electrochemical approach for the safety of environmental and ecological fields in broad scales.

One-step facile synthesis of SnO2@Nd2O3 nanocomposites for selective amidol detection in aqueous phase

In this approach, amidol, a toxic organic chemical, is used as a staining developer electrochemically detected by using binary SnO₂@Nd₂O₃ nanocomposites (NCs) by deposition onto a flat glassy carbon electrode (GCE).

Enzyme-free detection of uric acid using hydrothermally prepared CuO·Fe2O3 nanocrystals

Copper oxide doped iron oxide nanocrystals (CuO·Fe₂O₃ NCs) were prepared using a simple hydrothermal technique at low temperature in an alkaline medium.

A non-enzymatic electrochemical approach for l-lactic acid sensor development based on CuO·MWCNT nanocomposites modified with a Nafion matrix

Copper oxide decorated multi-walled carbon nanotube nanocomposites (CuO·MWCNT NCs) were prepared using a simple wet-chemical technique in basic medium.

Simultaneous detection of l-aspartic acid and glycine using wet-chemically prepared Fe3O4@ZnO nanoparticles: real sample analysis

An easy and reliable wet-chemical method was used to synthesize iron oxide doped zinc oxide nanoparticles (Fe₃O₄@ZnO NPs) at a low-temperature under alkaline medium.