Aspartic acid assisted one-step synthesis of stable CsPbX3@Asp-Cs4PbX6 by in situ growth in NH2-MIL-53 for ratiometric fluorescence detection of 4-bromophenoxybenzene

Design and application of dual-emission metal-organic framework-based ratiometric fluorescence sensors

Metal-organic frameworks (MOFs) are novel inorganic-organic hybridized crystals with a wide range of applications. In the last twenty years, fluorescence sensing based on MOFs has attracted much attention. MOFs can exhibit luminescence from metal nodes, ligands or introduced guests, which provides an excellent fluorescence response in sensing. However, single-signal emitting MOFs are susceptible to interference from concentration, environment, and excitation intensity, resulting in poor accuracy. To overcome the shortcomings, dual-emission MOF-based ratiometric fluorescence sensors have been proposed and rapidly developed. In this review, we first introduce the luminescence mechanisms, synthetic methods, and detection mechanisms of dual-emission MOFs, highlight the strategies for constructing ratiometric fluorescence sensors based on dual-emission MOFs, and classify them into three categories: intrinsic dual-emission and single-emission MOFs with luminescent guests, and non-emission MOFs with other luminescent materials. Then, we summarize the recent advances in dual-emission MOF-based ratiometric fluorescence sensors in various analytical industries. Finally, we discuss the current challenges and prospects for the future development of these sensors.

Biomolecules incorporated in halide perovskite nanocrystals: synthesis, optical properties, and applications

Halide perovskite nanocrystals (HPNCs) have emerged at the forefront of nanomaterials research over the past two decades. The physicochemical and optoelectronic properties of these inorganic semiconductor nanoparticles can be modulated through the introduction of various ligands. The use of biomolecules as ligands has been demonstrated to improve the stability, luminescence, conductivity and biocompatibility of HPNCs. The rapid advancement of this field relies on a strong understanding of how the structure and properties of biomolecules influences their interactions with HPNCs, as well as their potential to extend applications of HPNCs towards biological applications. This review addresses the role of several classes of biomolecules (amino acids, proteins, carbohydrates, nucleotides, etc.) that have shown promise for improving the performance of HPNCs and their potential applications. Specifically, we have reviewed the recent advances on incorporating biomolecules with HP nanomaterials on the formation, physicochemical properties, and stability of HP compounds. We have also shed light on the potential for using HPs in biological and environmental applications by compiling some recent of proof-of-concept demonstrations. Overall, this review aims to guide the field towards incorporating biomolecules into the next-generation of high-performance HPNCs for biological and environmental applications.

A gel fluorescence sensor based on CDs@SiO2/FeS2@MIPs for the visual detection of p-chlorophenol

There is a critical need for the rapid detection of p-chlorophenol produced by pesticide abuse and industrial wastewater discharge, which has been an urgent problem in the realm of environmental protection. Here, a green and environmentally friendly method was developed to prepare stable and low toxicity quantum dots. First, blue-green fluorescent FeS₂ quantum dots (B-FeS₂ QDs) were prepared with FeCl₃·6H₂O (an iron source) and L-cysteine (a capping agent) by the solvothermal method. By combining B-FeS₂ QDs with orange carbon dots (O-CDs), a CDs@SiO₂/FeS₂@MIPs visual fluorescence sensor for the selective detection of p-chlorophenol was constructed. Under optimum conditions, this sensor exhibited a detection limit of 1.265 μM with a linear range of 5.00-50.00 μM and was successfully applied to detect p-chlorophenol in real samples. Moreover, this sensor was successfully applied to visual semi-quantitative detection of p-chlorophenol. This work demonstrated that these sensors, based on FeS₂ QDs and CDs, had potentials for in situ and visual detection of environmental contaminants.