Nanozyme Inhibited Sensor Array for Biothiol Detection and Disease Discrimination Based on Metal Ion-Doped Carbon Dots

Abstract

Developing highly active and sensitive nanozymes for biothiol analysis is of vital significance due to their essential roles in disease diagnosis. Herein, two metal ion-doped carbon dots (M-CDs) with high peroxidase-like activity were designed and prepared for biothiol detection and identification through the colorimetric sensor array technique. The two M-CDs can strongly catalyze the decomposition of H 2 O 2 , accompanied by color changes of 3,3′,5,5′tetramethylbenzidine (TMB) from colorless to blue, indicating peroxidase-mimicking activities of M-CDs. Compared with pure carbon dots (CDs), M-CDs exhibited enhanced peroxidase-like activity owing to the synergistic effect between metal ions and CDs. However, due to the strong binding affinity between biothiols and metal ions, the catalytic activities of M-CDs could be inhibited by different biothiols to diverse degrees. Therefore, using TMB as a chromogenic substrate in the presence of H 2 O 2 , the developed colorimetric sensor array can form differential fingerprints for the three most important biothiols (i.e., cysteine (Cys), homocysteine (Hcy), and glutathione (GSH)), which can be accurately discriminated through pattern recognition methods (i.e., hierarchical clustering analysis (HCA) and principal component analysis (PCA)) with a detection limit of 5 nM. Moreover, the recognition of a single biothiol with various concentrations and biothiol mixtures was also realized. Furthermore, actual samples such as cells and sera can also be well distinguished by the as-fabricated sensor array, demonstrating its potential in disease diagnosis.

Photoluminescence–Electrochemiluminescence Dual-Mode Sensor Arrays for Histidine and Its Metabolite Discrimination and Disease Identification

“…Combined with the mathematics analysis technique, such as a principal component analysis (PCA), linear discriminant analysis, and hierarchical clustering analysis (HCA), , the characteristic fingerprints can be transformed into simple visualization modes, enabling discrimination among different target analytes. Thus, many sensor arrays have been developed to detect and differentiate a wide range of analytes, including ions, proteins, DNA, and even small molecules with a similar structure or chemical characteristics . Though widely used for the recognition of various target analytes, there is still no report on sensor arrays for the detection and identification of His and its metabolites.…”

Detection and discrimination of glutathione among biological thiols based on oxalyl dihydrazide decorated sulfur nanodots

“…This suggested the weaker hydrogen bond formation ability of Hcy, CA and 2-Me than GSH to compete with C–H bonds on PEG, which was responsible for the discrimination ability of ODH@S-dots towards GSH. 9…”

“…1 These critical physiological functions of biological thiols have spurred increased research interest in developing sensitive and selective methods for the detection and discrimination of Cys, Hcy, and GSH. [8][9][10][11] Among the recently reported methods, fluorescence assays are regarded as the most promising technology, because of their advantages of simple operation, noninvasive detection, and high sensitivity. 12,13 Many fluorescence assays have been reported for the sensitive detection of biological thiols.…”

“…16,17 Even though several works about selective detection of GSH have been reported, they still face the limitations of the utilization of toxic organic substances and heavy metal ions, low stability, and complicated molecular design and synthesis of the fluorescent probes. 9,16 Thus, it is still an urgent and challenging task to develop effective strategies for designing fluorescence assays for GSH with high sensitivity and discrimination ability to other biological thiols.…”

Distinct dual enzyme-like activities of Fe–N–C single-atom nanozymes enable discriminative detection of cellular glutathione

“…24 To this end, several nanozyme sensor arrays have recently been constructed. 25–27 However, they usually required tedious synthesis of multiple sensing elements, and the co-action between different nanozymes may compromise the selectivity. Thus, it is highly demanded to develop a simple yet efficient strategy based on nanozymes for discriminative detection of GSH in the complex intracellular environment.…”