Dipeptide Surface Modification and Ultrasound Boosted Phosphatase-Like Activity of the Ceria Nanozyme: Dual Signal Enhancement for Colorimetric Sensors

Abstract

The development of innovative nanozymes with superior enzyme-mimicking activities for colorimetric sensor applications has attracted substantial attention in recent years; however, their application has remained challenging in sensitive colorimetric detection owing to their low catalytic activities. The construction of a more efficient nanozyme-based catalytic system would therefore be expected to improve the detection sensitivities of colorimetric sensors. Herein, we report the development of a highly reactive phosphatase-like nanozyme (carnosine-modified nanoceria, CMNC) engineered by introducing distal imidazole-containing amino acid residues onto the nanoceria surfaces to mimic the reaction microenvironment of the native phosphatase. The obtained results showed that CMNC presented a significantly enhanced catalytic activity compared to the bare nanoceria, furthermore discovering that ultrasonic stimulation significantly enhanced the phosphatase-like catalytic performance of CMNC. Based on these findings, as a proof-of-concept demonstration, two ultrasensitive nanozyme-based colorimetric immunoassays were developed for quantifying the C-reactive protein and prostate-specific antigen. Benefiting from the surface modification and ultrasound-enhanced phosphatase-like activity of CMNC, this dual signal-enhancing strategy improved the performances of the corresponding colorimetric sensors, and an approximately 50-fold higher sensitivity was achieved compared to that of the bare nanoceria without ultrasonic irradiation. These results pave the way for the use of nanozymes in highly sensitive biosensors.

Transition-Metal-Based Nanozymes: Synthesis, Mechanisms of Therapeutic Action, and Applications in Cancer Treatment

“…Connecting modification groups to nanozymes represents a versatile strategy for precise modulation of catalytic activity, primarily accomplished through physical adsorption or chemical coupling to anchor ligands that can effectively modify the biocompatibility and substrate affinity of nanozymes. − For example, Chen et al reported the development of carboxylated chitosan (CC)-modified platinum nanoparticles (CC-PtNPs) with augmented ascorbate oxidase-like activity to accelerate the conversion of ascorbic acid (AA) to dehydroascorbic acid (DHAA), enabling detection of acid phosphatase (ACP) activity (Figure A) . As a control, chitosan was employed for the decoration of PtNPs (Ch-PtNPs).…”

Modulation of the enzyme-like activity of CuAsp nanozyme by gallic acid and the selective detection of bisphenol A in infant food packaging

“…[24][25][26][27] The modulation of nanozyme activities can be achieved through surface modication, which can be achieved through covalent immobilization of functional groups or electrostatic adsorption. [28][29][30] Such as Chen et al synthesized {110}-dominated CeO 2 nanorods (CeO 2 NR) with abundant defects on the surface and found that modication of atomically dispersed Au on the CeO 2 NR surface not only enhanced the original peroxidase-like (POD-like) activity but also obtained glucose oxidase-like (GO x -like) activity. 31 Gao's group constructed PTA/CeO 2 NZs by surface modifying multifunctional composite CeO 2 nanozymes (CeO 2 NZs) with nanoscale poly(tannic acid) (PTA) coatings, which exhibited enhanced superoxide dismutase-like (SOD-like) activity and higher free radical scavenging capacity than before.…”

Graphene quantum dot surface ligand and Co and Pt double-doping-engineered Co/Co3O4 nanozyme displaying superior performance to horseradish peroxidase and choline oxidase for the efficient degradation of rhodamine B without an activator

“…Nanozymes are a type of nanomaterial that possess high catalytic activity similar to natural enzymes under mild conditions. 1 Various nanozymes have been reported and widely used for sensing, 2 biomedicine, 3 energy storage, 4 catalysis, 5 and organic degradation. 1 Recently, the application of nanozymes in organic pollutant degradation has received increasing attention due to their good stability and low cost.…”

“…The first way is to modify functional molecules or the conductive 2D material on the surface of the nanozyme. 2,3 Modification with functional molecules alters the surface chemical environment of the nanozyme and endows it with some specific functions. 2,7 Ye et al reported the modification of CeO 2 with a dipeptide.…”