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Luminescent nanoclusters (NCs), with their easy preparation, ultrafine size, low toxicity, and excellent photostability have recently emerged as novel electrochemiluminescence (ECL) emitters. However, relatively low quantum yield (QY) in both aqueous and organic media has impeded their application in ECL emitter evolution. In this mini-review, we discuss the recent development of NCs in ECL with particular focus on their optical properties. We first classify the NCs according to composition and structure, and then summarize four aspects that affect QY, including environment effects, construction, valence state effects and aggregation-induced ECL. The ECL mechanisms based on NCs are elucidated as well. Finally, we briefly discuss the potential applications of NCs in tumor markers test, immunoassay and serum test. This review aims to provide a comprehensive summary of the progress of NCs in ECL, which will motivate researchers to develop NC chemistry and explore their future applications in ECL.

Glutathione (GSH) serves vital functions in biological systems and associates with various human diseases. In this work, a versatile electrochemiluminence (ECL) and a photoelectrochemical (PEC) "signal on" biosensing platform were developed for a sensitive assay of GSH by a Mn

In this work, a new 3D DNA nanosphere was ingeniously designed and fabricated, which was used to combine with multiple enzyme-free amplification strategy to develop a photoelectrochemical (PEC) biosensing platform for ultrasensitive detection of carcinoembryonic antigen (CEA). The 3D DNA nanostructure was self-assembled by base complementary pairing in a few minutes and rolling circle amplification (RCA) reaction. The intense photocurrent derived from Au NPs/ZnSe QDs can be effectively decreased by 3D DNA nanospheres assembled on the electrode, making photoelectric signal present “off” state. The specific binding of target CEA with its hairpin (HP1) aptamer opens HP1 structure, which initiated multiple enzyme-free strand displacement amplification (SDA) reaction and generated a large number of single strands DNA S1. Then S1 competitively binds to capture DNA on the electrode to release 3D DNA nanospheres, thus the photocurrent signal became “on” state for achieving amplified assay of target CEA. The proposed PEC biosensor exhibits excellent performance with a wide linear range of 1.0 fg/mL to 10 ng/mL and a low detection limit of 0.12 fg/mL for CEA, which was successfully applied for the assay of real serum samples with good precision. The reported strategy opens a new simple way for PEC biosensor using DNA nanostructure, showing huge potential in clinical application research.

Herein, a new multifunctional DNA nanotube (DNANT) was self-assembled and used to load Ru(phen)32+ and methylene blue (MB) as amplified signal probes for versatile electrochemiluminescence (ECL) and electrochemical (EC) “on–off” assays of Dam methylase (MTase) and aflatoxin B1 (AFB1). The DNA nanotube as a carrier could immobilize numerous MB or Ru(phen)32+ species in the double-stranded DNA (dsDNA) to significantly amplify signals, which enabled highly sensitive ECL and electrochemical detection of dual targets. The target Dam MTase first catalyzed the methylation of hairpin DNA (H1), and then the methylated DNA was cleaved by endonuclease DpnI to expose a single-strand DNA. After the Ru(phen)32+-DNANT or MB-DNANT signal probes were assembled to the electrode by hybridization, remarkable “signal on” states for amplified ECL or EC assays of MTase were obtained. Furthermore, in the presence of the target AFB1, the structure of DNANTs collapsed due to the specific binding of AFB1 to aptamer S2 in NTs, which...

In this work, we designed a new strategy for ultrasensitive detection of CEA based on efficient electrochemiluminescence (ECL) quenching of Ru(bpy)

In the present work, we designed a unique enzyme-aided multiple amplification strategy for sensitive electrochemiluminescence (ECL) detection of DNA by using the amplified gold nanoparticles (GNPS)-polyamidoamine (PAMAM)-CdSe quantum dots (QDs) signal probe. Firstly, the novel GNPS-PAMAM dendrimers nanostructure with good biocompatibility and electroconductibility contains many amino groups, which can load a large number of CdSe QDs to develop amplified ECL signal probe. Then, the presence of target DNA activated the enzyme-assisted polymerization strand-displacement cycling reaction, and a large number of the hairpin template was opened. Subsequently, the opened stem further interacted with the capture hairpin (HP) DNA on the electrode, and the GNPS-PAMAM-CdSe signal probe hybridized with the exposed stem of the HP to trigger the second new polymerization reaction. Meanwhile, the first cycle was generating abundant DNA triggers which could directly open the template. As a result of the cascade amplification technique, a large number of CdSe QDs signal probe could be assembled on the electrode, generating much amplified ECL signal for sensitive detection of target DNA. Thus, this novel QDs-based amplified ECL strategy holds great promise for DNA detection and can be further exploited for sensing applications in clinical diagnostics.