One-pot synthesis of a peroxidase-like nanozyme and its application in visual assay for tyrosinase activity

Application of a Dual-Probe Coloading Nanodetection System in the Process Monitoring and Efficacy Assessment of Photodynamic Therapy: An In Vitro Study

“…As a mussel-inspired catecholamine, PDA has drawn significant interest as an energy acceptor for constructing FRET-based biosensors, which could quench a variety of probes based on the fluorescein molecule by the FRET effect. − The FAM-aptamer/PDA nanocomplex remained “off” due to the fluorescence energy transfer between FAM-aptamer and PDA, thus resulting in the fluorescence quenching of the fluorophore adjacent to the surface of PDA. When the nanocomplex was transported into cells, the fluorescent group dissociated from the PDA surface as the aptamer combined with the target, which led to the disappearance of energy transfer and switched the fluorescent signal to an “on” state. − In this study, the fluorescein-labeled VEGF aptamer was combined with PDA-coated mesoporous silica nanoparticles (MSN@PDA NPs) to construct the nanosystem that could responsively detect changes in intracellular VEGF levels (Figure A).…”

Development of a Selective Assay of Tyrosine and Its Producing and Metabolizing Enzymes Utilizing Pulse-UV Irradiation-Induced Chemiluminescence

“…The analytical performance of the developed method was compared with the previously reported methods for the determination of tyrosinase activity ,− as abridged in Table S5. These methods suffer from several drawbacks, including the dependence on nonselective quenching of a fluorophore by the produced quinone from the enzymatic reaction, ,, the use of synthetic substrates that will react with tyrosinase in several ways different from natural substrates that could lead to false results, ,,,,, complicated synthesis of the sensing probes, ,,,, or the use of time-consuming fluorogenic reaction (1.5 h) . On the other hand, the proposed method is very simple and showed higher sensitivity than many of the previously reported methods − ,,, and similar sensitivity to others, ,,, and thus it could be a better choice for tyrosinase activity assay.…”

“…The analytical performance of the developed method was compared with the previously reported methods for the determination of tyrosinase activity 5,53−63 as abridged in Table S5. These methods suffer from several drawbacks, including the dependence on nonselective quenching of a fluorophore by the produced quinone from the enzymatic reaction, 58,59,61 the use of synthetic substrates that will react with tyrosinase in several ways different from natural substrates that could lead to false results, 53,54,56,57,60,62 complicated synthesis of the sensing probes, 53,54,56,57,63 or the use of time-consuming fluorogenic reaction (1.5 h). 5 On the other hand, the proposed method is very simple and showed higher sensitivity than many of the previously reported methods [53][54][55][56][57]60,61,63 and similar sensitivity to others, 5,58,59,62 and thus it could be a better choice for tyrosinase activity assay.…”

Recent advances in colorimetric sensors based on nanozymes with peroxidase-like activity

“…47 Among them, peroxidase is the most widely investigated nanozyme. [48][49][50] For the peroxidase-mimetic system, nanozymes can efficiently catalyze the chromogenic substrates, such as 3,3′,5,5′-tetramethylbenzidine (TMB), 51 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), 52 and o-phenylenediamine dihydrochloride (OPD), 4 to generate chromogenic products also accompanied by colorimetric signals in the presence of hydrogen peroxide (H 2 O 2 ). The mechanism of catalytic color involves nanozymes decomposing the O-O bond of H 2 O 2 into hydroxyl radicals ( • OH) with high oxidative capacity and then generating • OH that further oxidizes chromogenic substrates.…”