Simple and Cost-Effective Glucose Detection Based on Carbon Nanodots Supported on Silver Nanoparticles

Abstract

We present a new glucose oxidase (GOx)-mediated strategy for detecting glucose based on carbon nanodots supported on silver nanoparticles (C-dots/AgNPs) as nanocomplexes. The strategy involves three processes: quenching of C-dots' fluorescence by AgNPs, production of HO from GOx-catalyzed oxidation of glucose, and HO-induced etching of AgNPs. In the C-dots/AgNPs complex, AgNPs act as a "nanoquencher" to decrease C-dots fluorescence by surface plasmon-enhanced energy transfer (SPEET) from C-dots (donor) to AgNPs (acceptor). The HO formed by GOx-catalyzed oxidation of glucose etches the AgNPs to silver ions, thus freeing the C-dots from the AgNPs surfaces and restoring the C-dots' fluorescence. Therefore, the increase in fluorescence depends directly on the concentration of HO, which, in turn, depends on the concentration of glucose. The strategy allows the quantitative analysis of glucose with a detection limit of 1.39 μM. The method based on C-dots/AgNPs offers the following advantages: simplicity of design and facile preparation of nanomaterials, as well as low experimental cost, because chemical modification and separation procedures are not needed.

Highly efficient redox reaction between potassium permanganate and 3,3′,5,5′-tetramethylbenzidine for application in hydrogen peroxide based colorimetric assays

“…Thus, the actual concentration of glucose in serum sample was 4.45 mM, which agreed with the fact that the normal level of glucose in blood is between 3.9 and 6.1 mM. 35 It is worth mentioning that the GOx does not affect the redox reaction between KMnO 4 and TMB, when the concentration of GOx was lower than 2 mg mL À1 . Meanwhile, 10 ng mL À1 of GOx was enough to cause the detectable absorbance signal (Fig.…”

Fluorescent Nanobiosensors for Sensing Glucose

“…Moreover, the surface of carbon dots often consists of carboxylic groups ( COOH), amine groups ( NH 2 ), and other groups for further functionalization. A fluorescence turn-on strategy for glucose sensing was achieved by incorporating fluorescent carbon dots inside plasmonic silver nanoparticles, as shown in Figure 15 [ 115 ]. Fluorescent carbon dots were first encapsulated inside the plasmonic silver nanoparticles during the synthesis of silver nanoparticles.…”

“… Fluorescence turn-on strategy for glucose detection based on a combination of carbon nanodots supported on silver nanoparticles and GOx-mediated oxidation of glucose. Reprinted with permission from Reference [ 115 ], Copyright (2016) American Chemical Society. …”

Controlled Synthesis of Porous Co3O4 Nanostructures for Efficient Electrochemical Sensing of Glucose

“…In recent years, great efforts have been devoted to the development of highly sensitive and selective, cost-effective detectors for glucose in pharmaceuticals, food, and clinical diagnostics [1], due to their risk of increasing cholesterol content, food allergies, and diabetes. Among various methods, using an electrochemical sensor is recognized as one of the most promising techniques compared to its counterparts including optical [2], thermometric [3], and fluorescent [4] sensors, owing to its high sensitivity, reliability, and affordable cost.…”