One-Pot, In-Situ Synthesis of 8-Armed Poly(Ethylene Glycol)-Coated Ag Nanoclusters as a Fluorescent Sensor for Selective Detection of Cu2+

Abstract

Fluorescent nanomaterials, such as quantum dots, have developed rapidly in recent years and have been significantly developed. Herein, we demonstrate a facile, one-pot, and in-situ synthesis strategy to obtain fluorescent silver nanoclusters (AgNCs) coated with eight-armed poly (ethylene glycol) polymers (8PEG-AgNCs) via a direct gel-mediated process. During the synthesis, ammonium (NH3) served as the crosslinker for the gel formation via a amine-type Michael addition reaction. This hydrogel can be used as a template to synthesize AgNCs using its volume-limiting effect. The in-situ generation of AgNCs takes place inside the nanocages of the formed gels, which guarantees the homogenous distribution of AgNCs in the gel matrix, as well as the efficient coating of PEG on the nanoclusters. After the degradation of gels, the released 8PEG-AgNCs nanohybrids showed strong blue fluorescence and exhibited long-term stability in aqueous solution for nearly one year. Results showed that the fabricated sensor revealed excellent fluorescent sensitivity for the selective detection of Cu2+ with a detection limit of 50 nM and a wide linear detection range of 5–100 μM. It is proposed that the greater cross-linking density leads to smaller gel pores and allows the synthesis of AgNCs with fluorescent properties. These results indicate that this novel hydrogel with certain biodegradation has the potential to be applied as a fluorescent sensor for catalytic synthesis, fluorescence tracing in cells, and fluorescence detection fields. Meanwhile, the novel design principle has a certain versatility to accelerate the development and application of other kinds of metal nanoclusters and quantum dots.

MoS2 QDs/8-Armed Poly(Ethylene Glycol) Fluorescence Sensor for Three Nitrotoluenes (TNT) Detection

“…In our previous work, the 8PEG hydrogel was used as a template to synthesize AgNCs. [ 24 ] The formation was due to the volume-limiting effect of 8PEG networks to AgNCs. The AgNCs formed inside the nanocages of the formed 8PEG gels.…”

Drug delivery systems based on polyethylene glycol hydrogels for enhanced bone regeneration

“…Since intramolecular aggregation prevents cross-linking of the chain, the eight-arm PEG has a tighter structure, resulting in a smaller binding capacity. The many structures of the eight-arm PEG will inevitably lead to a prolonged gel-forming time ( Zhang et al, 2020 ).…”

Progress in the Development of Biosensors Based on Peptide–Copper Coordination Interaction

“…After being complexed by the peptide, Cu 2+ , with a paramagnetic property, quenched the fluorescence of the dansyl group near the binding center via electron or energy transfer from the excited fluorophore to the coordinated Cu 2+ . In addition, metal NCs as the fluorescent reporters have attracted extensive attention because of their promising properties (e.g., easy synthesis, good biocompatibility, and high stability) [ 36 , 37 , 38 ]. In order to evaluate the selectivity and anti-interference of the sensor, other common metal ions (K + , Na + , Mg 2+ , Fe 2+ , Cu + , Co 2+ ) and plasma were determined as the control experiments.…”