A Novel Sensitive Luminescence Probe Microspheres for Rapid and Efficient Detection of τ-Fluvalinate in Taihu Lake

Fluorescence-Based Sensing of Pesticides Using Supramolecular Chemistry

The detection of pesticides in real-world environments is a high priority for a broad range of applications, including in areas of public health, environmental remediation, and agricultural sustainability. While many methods for pesticide detection currently exist, the use of supramolecular fluorescence-based methods has significant practical advantages. Herein, we will review the use of fluorescence-based pesticide detection methods, with a particular focus on supramolecular chemistry-based methods. Illustrative examples that show how such methods have achieved success in real-world environments are also included, as are areas highlighted for future research and development.

Development of fluorescence oligonucleotide probes based on cytosine- and guanine-rich sequences

The properties of cytosine- and guanine-rich oligonucleotides contributed to employing them as sensing elements in various biosensors. In this paper, we report our current development of fluorescence oligonucleotide probes based on i-motif or G-quadruplex forming oligonucleotides for cellular measurements or bioimaging applications. Additionally, we also focus on the spectral properties of the new fluorescent silver nanoclusters based system (ChONC12-AgNCs) that is able to anchor at the Langmuir monolayer interface, which is mimicking the surface of living cells membrane.

Sensors Applied for the Detection of Pesticides and Heavy Metals in Freshwaters

Water is essential for every life living on the planet. However, we are facing a more serious situation such as water pollution since the industrial revolution. Fortunately, many efforts have been done to alleviate/restore water quality in freshwaters. Numerous sensors have been developed to monitor the dynamic change of water quality for ecological, early warning, and protection reasons. In the present review, we briefly introduced the pollution status of two major pollutants, i.e., pesticides and heavy metals, in freshwaters worldwide. Then, we collected data on the sensors applied to detect the two categories of pollutants in freshwaters. Special focuses were given on the sensitivity of sensors indicated by the limit of detection (LOD), sensor types, and applied waterbodies. Our results showed that most of the sensors can be applied for stream and river water. The average LOD was72.53±12.69 ng/ml (n=180) for all pesticides, which is significantly higher than that for heavy metals (65.36±47.51 ng/ml,n=117). However, the LODs of a considerable part of pesticides and heavy metal sensors were higher than the criterion maximum concentration for aquatic life or the maximum contaminant limit concentration for drinking water. For pesticide sensors, the average LODs did not differ among insecticides (63.83±17.42 ng/ml,n=87), herbicides (98.06±23.39 ng/ml,n=71), and fungicides (24.60±14.41 ng/ml,n=22). The LODs that differed among sensor types with biosensors had the highest sensitivity, while electrochemical optical and biooptical sensors showed the lowest sensitivity. The sensitivity of heavy metal sensors varied among heavy metals and sensor types. Most of the sensors were targeted on lead, cadmium, mercury, and copper using electrochemical methods. These results imply that future development of pesticides and heavy metal sensors should (1) enhance the sensitivity to meet the requirements for the protection of aquatic ecosystems and human health and (2) cover more diverse pesticides and heavy metals especially those toxic pollutants that are widely used and frequently been detected in freshwaters (e.g., glyphosate, fungicides, zinc, chromium, and arsenic).

Development of Novel Bioreactor Control Systems Based on Smart Sensors and Actuators

Bioreactors of various forms have been widely used in environmental protection, healthcare, industrial biotechnology, and space exploration. Robust demand in the field stimulated the development of novel designs of bioreactor geometries and process control strategies and the evolution of the physical structure of the control system. After the introduction of digital computers to bioreactor process control, a hierarchical structure control system (HSCS) for bioreactors has become the dominant physical structure, having high efficiency and robustness. However, inherent drawbacks of the HSCS for bioreactors have produced a need for a more consolidated solution of the control system. With the fast progress in sensors, machinery, and information technology, the development of a flat organizational control system (FOCS) for bioreactors based on parallel distributed smart sensors and actuators may provide a more concise solution for process control in bioreactors. Here, we review the evolution of the physical structure of bioreactor control systems and discuss the properties of the novel FOCS for bioreactors and related smart sensors and actuators and their application circumstances, with the hope of further improving the efficiency, robustness, and economics of bioprocess control.

Molecularly Imprinted Polymer-Based Hybrid Materials for the Development of Optical Sensors

We report on the development of new optical sensors using molecularly imprinted polymers (MIPs) combined with different materials and explore the novel strategies followed in order to overcome some of the limitations found during the last decade in terms of performance. This review pretends to offer a general overview, mainly focused on the last 3 years, on how the new fabrication procedures enable the synthesis of hybrid materials enhancing not only the recognition ability of the polymer but the optical signal. Introduction describes MIPs as biomimetic recognition elements, their properties and applications, emphasizing on each step of the fabrication/recognition procedure. The state of the art is presented and the change in the publication trend between electrochemical and optical sensor devices is thoroughly discussed according to the new fabrication and micro/nano-structuring techniques paving the way for a new generation of MIP-based optical sensors. We want to offer the reader a different perspective based on the materials science in contrast to other overviews. Different substrates for anchoring MIPs are considered and distributed in different sections according to the dimensionality and the nature of the composite, highlighting the synergetic effect obtained as a result of merging both materials to achieve the final goal.

Fabrication of AO/LDH fluorescence composite and its detection of Hg2+ in water

Divalent mercury ion (Hg²⁺) is one of the most common pollutants in water with high toxicity and significant bioaccumulation, for which sensitive and selective detection methods are highly necessary to carry out its detection and quantification. Fluorescence detection by organic dyes is a simple and rapid method in pollutant analyses and is limited because of quenching caused by aggregation dye molecules. Hydrotalcite (LDH) is one of the most excellent carrier materials. In this study, an organic dye acridine orange (AO) was successfully loaded on the LDH layers, which significantly inhibited fluorescence quenching of AO. The composite AO/LDH reaches the highest fluorescence intensity when the AO initial concentration is 5 mg/L. With its enhanced fluorescent property, the composite powder was fabricated to fluorescence test papers. The maximal fluorescence intensity was achieved with a pulp to AO/LDH ratio of 1:5 which can be used to detect Hg²⁺ in water by naked eyes. Hg²⁺ in aqueous solution can be detected by instruments in the range of 0.5 to 150 mM. The novelty of this study lies on both the development of a new type of mineral-dye composite material, as well as its practical applications for fast detection.