Nanoclusterzyme for Dual Colorimetric Sensings: A Case Study on [Au₁₄(Dppp)₅I₄]²⁺

Abstract

The enzymatic activity of atomically precise metal nanoclusters has recently been recognized; however, the number of nanoclusterzymes is very small. Besides, the applications of nanoclusterzyme wait to be explored. Herein, a novel nanoclusterzyme is synthesized and its structure is majorly resolved by single‐crystal X‐ray diffraction and mass spectrometry, which reveal that the nanocluster consists of an Au13 icosahedron capped by an exterior shell including four I, three Dppp (1,3‐bis(diphenylphosphino) propane) ligands, and a rarely reported Dppp‐Au‐Dppp handle staple, which contributes a lot to the enzyme activity of [Au14(Dppp)5I4]2+ nanocluster. The as‐obtained nanocluster can catalyze oxygen to O2•− under visible light irradiation with a specific activity up to 0.182 U·mg−1 and lead to the blue color of 3,3′,5,5′‐tetramethylbenzidine (TMB) in both solution and solid states. With the addition of acetylcholinesterase (AChE), the blue color of (Au14 + TMB) solution system disappears due to the nanoclusterzyme activity inhibition, but the further addition of organophosphorus pesticides (OPs) into the above mixture can restore the nanoclusterzyme and recover the blue color. Based on the color turn‐off and on, the various nanoclusterzyme‐containing systems are used to colorimetrically sense AChE and OPs with the detection limits reaching 0.04 mU·mL−1 and 0.02 ng·mL−1, respectively.

Trace Amount of Bi-Doped Core–Shell Pd@Pt Mesoporous Nanospheres with Specifically Enhanced Peroxidase-Like Activity Enable Sensitive and Accurate Detection of Acetylcholinesterase and Organophosphorus Nerve Agents

“…According to the calibration plot shown in Figure d, a strong correlation can be observed between absorbance and the concentration of OP within the range of 0.1 to 100 ng mL –1 . The LOD is as low as 0.06 ng mL –1 , which is notably lower than that of the majority of reported methods − (Table S4). Additionally, the LOD complies with the Chinese National Food Safety Standards (GB/T 2763-2016) regarding the maximum permissible level of OPs in food.…”

Photoluminescence Quenching of Hydrophobic Ag29 Nanoclusters Caused by Molecular Decoupling during Aqueous Phase Transfer and EmissionRecovery through Supramolecular Recoupling

“…Previous studies have demonstrated that the emission of hydrophobic nanoclusters might be weakened (or even quenched) in the presence of water, although the underlying mechanism remains unclear [48] . In this context, the development of an amphiphilic nanocluster system with manipulable structures and maintainable emissions in the oil/aqueous phase is conducive to promoting the downstream applications of fluorescent clusters [49–54] . Such a nanocluster system is helpful for comprehensively studying the aforementioned fluorescence weake ning/quenching mechanism and can facilitate the PL manipulation of hydrophobic nanoclusters in the aqueous phase at the atomic level.…”

Multicolor Biosensor of Hyaluronidase by the Regulation of Enzyme-Like Catalytic Activity of Au Nanoclusters through Changes in the Aggregation State

“…By etching the longitudinal absorption band through the peroxidase-catalyzed oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) by H 2 O 2 under acidic conditions, the aspect ratio can be adjusted, thereby visually presenting various color changes. Colorimetric analysis methods constructed based on Au NPs, owing to their simplicity and lack of need for equipment, had been applied to detect different targets. − Compared with traditional colorimetric analysis methods using organic dyes as substrates, this approach, characterized by high extinction coefficients and a variety of color changes, enhances detection sensitivity and visual recognition capability. − In previous studies, our research team has developed many sensors based on the etching of Au NRs. These sensors have also demonstrated strong detection capabilities in the analysis of real samples. − …”