Synergistic electron transfer effect-based signal amplification strategy for the ultrasensitive detection of dopamine

Functional nanostructures in analytical chemistry: new insights into the optical and electrochemical sensing of animal hormones in food, environmental and biological samples

“…In this method, the AgNPs and dopamine-quinone quenched the emission intensity of SiNPs effectively via synergistic electron transfer effect. 96 Fig. 11a illustrates the mechanism for the detection of dopamine, where under the optimal alkaline condition, dopamine is responsible for the reduction of Ag + to AgNPs and dopamine gets oxidized to dopamine-quinone, which act as an electron acceptor.…”

Signaling strategies of silver nanoparticles in optical and electrochemical biosensors: considering their potential for the point-of-care

“…This “superquenching,” exhibiting Stern–Volmer quenching constants several orders of magnitude larger than those of normal quenching processes, has been exploited to develop sensitive, rapid, and homogeneous biosensors [ 39 ]. In the last years, AgNPs were employed as quencher in combination with various other fluorescent nanomaterials like metal–organic frameworks [ 66 ], carbon dots [ 67 ], or silica nanoparticles [ 68 ]. These FRET sensors can either be employed for analytes which are able to cross-link donor and acceptor (Fig.…”

“…These FRET sensors can either be employed for analytes which are able to cross-link donor and acceptor (Fig. 2 , d), such as miRNA [ 66 ], or analytes which are able to reduce Ag + and form the quenching AgNPs in situ, e.g., ascorbic acid [ 67 ] or dopamine [ 68 ]. These sensors can be developed in “turn-on” or “turn-off” mode.…”

“…nanofibers • Advances in nanoengineering • Finely tuned surfaces • Well-thought-through systems [ 61 , 63 , 64 ] FRET • Extremely effective quenching (“superquenching”) • Simplicity, rapidity, sensitivity • Various possible combinations of materials • Limits of employed fluorescent dye, e.g. photostability, quantum yield, photobleaching • Research still in proof-of-principle stage • Adaption of principles to the POC [ 66 – 68 ] Fluorescence of AgNC • Tunable emission, high multiplexing capabilities • Simple synthesis • High quantum yield, narrow emission bands, excellent biocompatibility • Unknown stability in biological fluids • In situ synthesis of AgNCs • More application examples in biological matrices • Confirmation of long-term stability of AgNCs [ 69 , 71 , 72 ] Electrochemical Ag NPs, aggregates, or nanocomposites as labels • Simple, sensitive, fast, low-cost, high throughput, easy miniaturization • Possible one-step assay • Huge signal amplification • Flexibility due to big amount of possible combinations (nanocomposites) • Surface modification may hinder electrochemical conversion • Modification via physisorption decreases performance, stability • Prevention of Ag oxidation, (unspecific) AgNP aggregation • Use of specific linkers • Drying in stabilizing matrices, stabilizing shells [ 90 , 92 , 95 ] Ag + reduction, Ag deposition • Combination with established enzyme systems • Reagent addition after sample addition • Often long reaction times • Proper catalyzing systems • Flow-injection analysis might enable automatic reagent addition [ 96 , 97 , 99 ] AgNPs as electrode modifier • Easy, ...…”

A mechanochemically synthesized porous organic polymer derived CQD/chitosan–graphene composite film electrode for electrochemiluminescence determination of dopamine

“…As an important catecholamine neurotransmitter, dopamine (DA) plays a critical role in hormonal, renal, cardiovascular and central nervous system (CNS) functions of humans. 1 An abnormal level of DA in biological fluids is often associated with neurological disorders. Hence, it is generally regarded as an indicator for the diagnosis of several neurological diseases.…”