QDs Based Photoelectrochemical Sensors for Detection of Ascorbic Acid

By fixing Quantum Dots (QDs) on gold electrodes with dithiol compounds, a novel Ascorbic Acid sensor without any redox mediator was desighed. First, the fabrication process of sensor was described.Sencond, the characteristics of the sensor were investigated. Third,the sensor was tested in Ascorbic Acid solutions of different concentrations.From the results,it shows that the performance of photoelectrochemical sensor were influenced by the bias voltage and the amplitude of photocurrent changed with the Ascorbic Acid concentration linearly in detection range.

Synthesis of Ag–Cu alloy nanosheets for ascorbic acid detection

Metal alloy nanosheets play a very important role as catalysts, which also show obvious advantages in the field of biosensor. Compared with traditional methods, such as enzyme method, gas chromatography or optical absorbance, the detection of ascorbic acid is simpler and more stable by spectroscopy. Ag–Cu alloy nanosheets with a thickness of about 1–3 nm and an average lateral size of 3–5 nm were synthesized in this study by the soft template method. These nanosheets were used to construct a sensor for measuring the concentration of ascorbic acid. The initial UV-Vis absorption peaks for the Ag–Cu alloy nanosheets in aqueous solution were effectively quenched upon addition of ascorbic acid. As the ascorbic acid concentration was in the range of 5–250 mmol/L changes, the UV absorbance intensity for the sensor also changed. Because of its wide detection range, high sensitivity, and excellent stability, the Ag–Cu alloy sensor method may be an excellent alternative to the traditional ascorbic acid measure method.

Self-Powered Flexible Sour Sensor for Detecting Ascorbic Acid Concentration Based on Triboelectrification/Enzymatic-Reaction Coupling Effect

Artificial sensory substitution systems can mimic human sensory organs through replacing the sensing process of a defective sensory receptor and transmitting the sensing signal into the nervous system. Here, we report a self-powered flexible gustation sour sensor for detecting ascorbic acid concentration. The material system comprises of Na2C2O4-Ppy with AAO modification, PDMS and Cu wire mesh. The working mechanism is contributed to the triboelectrification/enzymatic-reaction coupling effect, and the device can collect weak energy from body movements and directly output triboelectric current without any external power-units. The triboelectric output is affected by AA concentration, and the response is up to 34.82% against 15.625 mM/L of AA solution. Furthermore, a practical application in detecting ascorbic acid concentration of different drinks has been demonstrated. This work can encourage the development of wearable flexible electronics and this self-powered sour sensor has the potential that can be acted as a kind of gustatory receptors to build electronic tongues.

ASCORBIC ACID CONCENTRATION AND PRETERM PREMATURE RUPTURE OF MEMBRANES (PPROM)

Pprom (preterm premature rupture of membranes )is one of the most common complication of pregnancy contributing to major fetal morbidity and mortality. So it is important to study causes like micronutrient deficiency which can lead to pprom so that it can be prevented and hence fetal complications can be reduced.Place of study: Department of Obstetrics & Gynecology, Jawahar Lal Nehru Medical College and Hospital, Bhagalpur, Bihar.Duration of study: period of 1 year. Prospective randomised study.

Effect of foliar sodium selenite biofortification on cauliflower yield, nutritional value and antioxidant status

Relevance. Biofortification of agricultural crops with selenium is considered to be the most promising method for the human selenium status optimization.Methods. Effect of foliar biofortification of cauliflower, Polyarnaya Zvezda cv, with sodium selenate of different concentrations on yield, selenium content and biochemical characteristics of plants were investigated.Results. Enrichment of plants with selenium increased yield by 1.23-1.31 times, sugar content – 1.6 times, ascorbic acid concentration – 1.52-2 times. On the contrary, the treatment did not affect pholyphenol content and antioxidant activity of ethanolic extracts of plants. Selenium accumulation levels decreased according to inflorescences > leaves > roots. Sodium selenate solution at 75 mg/L concentration increased mass of cauliflower leaves 1.9 times and roots – 1.5 times. Consumption of 100 g of cauliflower fortified with 50 mg/L sodium selenate solution provided 100% of the daily adequate selenium consumption level. Utilization of higher sodium selenate concentrations ensured 127% and 418% of the daily adequate consumption level in case of 75 mg/L and 100 mg/L concentrations respectively. Taking into account insignificant differences between sugar content and antioxidants in cauliflower inflorescences fortified with different doses of selenium the most suitable concentration to be used was 50 mg/L.