Dual channel ion imprinted fluorescent polymers for dual mode simultaneous chromium speciation analysis

Construction of a thermoresponsive molecularly imprinted biomimetic hydrogel-based virus sensor and non-invasive cyclable detection of EV71

A thermoresponsive molecularly imprinted hydrogel sensor was constructed for the specific selective recognition of enterovirus 71 (EV71). Due to the introduction of the thermosensitive monomer N-isopropylacrylamide (NIPAM), when the imprinted hydrogel is incubated with the virus at 37℃, the surface specific imprinting cavity will specifically recognize and capture the target virus EV71. When the temperature rises to 45℃, the combined EV71 is rapidly released due to changes in the shape and function of the imprinted sites. The MIP hydrogel-based viral sensor developed recognized, captured, and released the target virus in a non-invasive way. The imprinting factor of the target virus was 5.2, suggesting high selectivity, and the detection limit was 7.1 fM, suggesting high sensitivity. Detection was rapid, as adsorption equilibrium was achieved within 30 min. This method provides a new sustainable avenue for the simple and rapid detection of viruses.

The construction of dual-emissive ratiometric fluorescent probes based on fluorescent nanoparticles for the detection of metal ions and small molecules

With the rapid development of fluorescent nanoparticles (FNPs), such as CDs, QDs, and MOFs, the construction of FNP-based probes has played a key role in improving chemical sensors. Ratiometric fluorescent probes exhibit distinct advantages, such as resistance to environmental interference and achieving visualization. Thus, FNP-based dual-emission ratiometric fluorescent probes (DRFPs) have rapidly developed in the field of metal ion and small molecule detection in the past few years. In this review, firstly we introduce the fluorescence sensing mechanisms; then, we focus on the strategies for the fabrication of DRFPs, including hybrid FNPs, single FNPs with intrinsic dual emission and target-induced new emission, and DRFPs based on auxiliary nanoparticles. In the section on hybrid FNPs, methods to assemble two types of FNPs, such as chemical bonding, electrostatic interaction, core satellite or core-shell structures, coordination, and encapsulation, are introduced. In the section on single FNPs with intrinsic dual emission, methods for the design of dual-emission CDs, QDs, and MOFs are discussed. Regarding target-induced new emission, sensitization, coordination, hydrogen bonding, and chemical reaction induced new emissions are discussed. Furthermore, in the section on DRFPs based on auxiliary nanoparticles, auxiliary nanomaterials with the inner filter effect and enzyme mimicking activity are discussed. Finally, the existing challenges and an outlook on the future of DRFP are presented. We sincerely hope that this review will contribute to the quick understanding and exploration of DRFPs by researchers.

Molecularly Imprinted Polymer-Based Sensors for Priority Pollutants

Globally, there is growing concern about the health risks of water and air pollution. The U.S. Environmental Protection Agency (EPA) has developed a list of priority pollutants containing 129 different chemical compounds. All of these chemicals are of significant interest due to their serious health and safety issues. Permanent exposure to some concentrations of these chemicals can cause severe and irrecoverable health effects, which can be easily prevented by their early identification. Molecularly imprinted polymers (MIPs) offer great potential for selective adsorption of chemicals from water and air samples. These selective artificial bio(mimetic) receptors are promising candidates for modification of sensors, especially disposable sensors, due to their low-cost, long-term stability, ease of engineering, simplicity of production and their applicability for a wide range of targets. Herein, innovative strategies used to develop MIP-based sensors for EPA priority pollutants will be reviewed.

One-pot synthesis of folic acid modified carbonized polymer dots with red emittision for selective imaging of cancer cells

Carbonized polymer dots (CPDs), as a novel fluorescent material, have broad application prospects in the fields of bio-imaging, bio-sensors, disease diagnosis and photovoltaic devices due to their low cost, low toxicity, easy modification and little environmental impact. In this paper, folic acid (FA) modified CPDs (FA-CPDs) are synthesized from p-Phenylenediamine (p-PD) and FA molecules using a traditional one pot hydrothermal reaction in order to detect cancer cells containing a folate receptor (FR). The synthesized FA-CPDs were characterized by transmission electron microscopy, Fourier transfrom infrared spectroscopy, x-ray photoelectron spectroscopy, x-ray diffraction, UV-vis and fluorescence techniques. The red fluorescence emission is realized by doping phosphorus atoms into the carbonized polymer. Upon excitation at 513 nm, the maximum emission wavelength of FA-CPDs aqueous solution was obtained at 613 nm. Moreover, the as-prepared FA-CPDs exhibit excellent excitation-independent behavior and good stability with high quantum yield (QY) at about 30.6%. The binding of FA-CPDs with FRs on cancer cells produces target recognition and enters the cells through endocytosis. Additionally, it is worth noting that FA-CPDs have good biocompatibility and imaging in HeLa cells has been successfully achieved. Therefore, our FA-CPDs have potential applications as biocompatibility probes for cancer diagnosis and treatment.