An overview of sensors and sensing materials for heavy metals in aqueous environments

Effect of Ionic Strength and pH on the Sorption of Heavy Metals onto Polyaniline Copolymers in Aqueous Solutions

Polyaniline (PANI) and two copolymers, poly(aniline-co-o-toluidine) (PoTOL-50) and poly(aniline-co-o-anisidine) (PoANI-50) were synthesized with equal input ratios (1:1) to enhance PANI as sensing material for the sensing of various heavy metal analytes in aqueous solutions. The polymers were evaluated for both their sensitivity and selectivity toward four heavy metals (Ba2+, Cd2+, Cu2+, and Ni2+) and two common matrix interferents (Ca2+ and Mg2+) at 10 and 40 ppm. The effect of pH and ionic strength of the aqueous solutions on the sensitivity and selectivity was also evaluated. All three polymers showed high sensitivity and selectivity to Ba2+. Varying the pH and ionic strength of solutions did not show significant differences in either the selectivity or the sensitivity of the polymers.

Exploration on flexible wearable sensor motion monitoring based on novel functional polymer conjugated materials

With the continuous development of flexible electronics, multi-functional device integration, artificial intelligence technology, etc., flexible wearable sensors are playing an increasingly important role in people's daily motion monitoring. However, current flexible wearable sensors have problems such as low accuracy, poor real-time performance, and poor stability in motion monitoring, which seriously hinder the better application of flexible wearable sensors and are not conducive to the collection and monitoring of motion signals. To this end, this paper designed a flexible wearable sensor motion monitoring system and tested its performance through the preparation and performance research of new functional polymer conjugated materials. The research results show that the motion monitoring system designed based on the new functional polymer conjugated material flexible wearable sensor has good monitoring accuracy and real-time performance. When the output data is 500 pieces, the running monitoring accuracy reaches 95.4%, and the monitoring feedback time is 0.321 s; the high jump movement monitoring accuracy rate reaches 97%, and the monitoring feedback time is 0.287 s; the long jump movement monitoring accuracy rate reaches 96%, and the monitoring feedback time is 0.296 s. This shows that the flexible wearable sensor motion monitoring system of this paper has better performance and can meet the current demand for accuracy and real-time motion monitoring. This study highlights the impact of new functional polymer conjugated materials on flexible wearable sensors, helping to further solve the deficiencies of flexible wearable sensors in sports monitoring and promote their better development.

Special Issue on “Tailoring Polymeric Materials for Specific Applications”

Polymers are a vast class of materials that are highly tailorable to a wide variety of applications and can be modified in numerous ways [...]

Development of an MFC-biosensor for determination of Pb+2: an assessment from computational fluid dynamics and life cycle assessment perspectives

Microbial fuel cell (MFC)-based biosensor sensing has emerged as an innovative approach to in situ and immediate monitoring of substrate concentration. MFC-biosensor uses bioanode as a sensing element. In this study, the performance of MFC-biosensor, operated with Pb⁺², was studied at different hydraulic retention times (HRTs). The HRT ranges were 0.5, 1, and 2 days. The power density generation increased with the decreasing HRT. The highest achievable power density was obtained at HRT of 1 days with the density value of 597 mW/m². The power density produced in the MFC system was stored in the energy storage system. The computational fluid dynamics (CFD) method simulates detailed three-dimensional flow and heat transfer properties in reactors and provides information about potential reactor design. CFD was chosen to simulate the concentration distribution of the substrate in the MFC in different reactor type and different HRTs. It was observed that there was good turbulence in the reactor in a two day HRT and the reactor volume was used effectively. Life cycle assessment (LCA) was performed at 1 day with the highest power density. An LCA was implemented to the production and operation processes of a microbial fuel cell. According to the results, these two processes caused 4.23 × 10^-6 loss of healthy years, extinction of 1.3 × 10^-8 species in a year and loss of $ 0.33 source availability. The emissions to air, water, and soil were also calculated. These results showed that MFC-biosensor provided information on the rate of biodegradation processes.