Biomolecule-functionalized Au nanoclusters (AuNCs) have drawn great interest in the electrochemiluminescence (ECL) field due to their unique optical/electrical properties, biocompatibility, and versatile bioapplication potentials. Herein, we proposed a two-in-one ECL probe of immunoglobulin Gencapsulated AuNCs (IgG-AuNCs) for the development of a highperformance ECL immunoassay (ECLIA) platform. The IgG-AuNCs were not only used as an ECL probe due to their excellent anodic ECL performance with triethylamine (TEA) as a coreactant but also used as the biorecognition element because of their wellretained bioactivity of the IgG. As a proof of concept, a new type of competitive immunosensing platform has been applied to detect IgG representing several merits of facile preparation, rapid detection, sample saving, and good analytical performance. The sensing platform exhibited a linear range of 0.5−50,000 ng/mL with a limit of detection of 0.06 ng/mL for IgG detection with high selectivity. In addition, this convenient ECLIA platform also performed well in real serum sample detection. Notably, our work not only proved the "two-in-one" immuno-AuNC probe-based ECLIA strategy but also developed a rational framework for study of ECL bioassay platforms based on multifunctional AuNCs and other related nanomaterials.

Screening high-performance anodic electrochemiluminescence (ECL) systems with low triggering potential is a promising way to broaden their applications. In addition to electrochemiluminophore, co-reactant also plays an important role in the ECL process, since the oxidation of co-reactants is one of the most important steps in the anodic ECL process. Herein, a novel co-reactant-mediated high-performance low-potential Au nanocluster (AuNC)-based ECL system has been successfully developed. Benefiting from the isopropyl substitution and hydroxyl addition to the triethylamine (TEA), the BSA-AuNC/2-(diisopropylamino)­ethanol (DIPEA-OH) ECL system achieved higher energy efficiency at a lower potential of 0.75 V. In addition, compared with the BSA-AuNC/TEA system, the ECL intensity and quantum yield (Φ ECL) with DIPEA-OH as a co-reactant increased 22.34-fold and 13-fold (as high as 68.17%), respectively. Based on the low potential, high Φ ECL of the AuNC/DIPEA-OH ECL system, a sandwich-type immunosensor has been constructed for a highly selective SARS-CoV-2 N protein assay. In the absence of any complex signal amplification strategies, the ECL immunosensor for the SARS-CoV-2 N protein detection showed a linear range of 0.001–100 ng/mL and a detection limit of 0.35 pg/mL. Moreover, the ECL platform had good reproducibility and stability and exhibited acceptable detection performance in the detection of actual serum samples. This work established a framework for in-depth design and study of anode ECL co-reactants for AuNCs and other luminophores, and expanded the potential application of ECL sensors in the clinical diagnosis of COVID-19.

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Background: Firstly, we aimed to compare the differences of higher-order chromatin structure between nasopharyngeal carcinoma (NPC) and normal nasopharyngeal tissues. The second objective was to analyze the specific chromatin interaction site of NPC and the NPC-related genes regulated by this interaction site. Methods: We included 6 NPC patients and 6 healthy controls to obtain the sequencing results of highestthroughput chromosome conformation capture (Hi-C) technique, followed by further analysis of the specific chromatin interaction sites in NPC. Results:We found an abnormal ultra-long distance interaction site on the chromosome 7p in the CNE210 sample, which was caused by a fusion gene SEPT7P2-PSPH. Additionally, a significant interaction site between chromosome 8q and 3p was revealed in the samples CNE25, CNE29, and CNE211, which was the interaction between 1.5 kb downstream of ASAP1 and 0.8 kb upstream of CTNNB1 gene. Further quantitative polymerase chain reaction (qPCR) revealed that ASAP1 and CTNNB1 genes were more highly expressed in CNE25, CNE29, and CNE211 than in the Np group, preliminarily indicating that this interaction site was likely related to the high expression of ASAP1 and CTNNB1 in NPC.Conclusions: Through Hi-C analysis, we analyzed the specific chromatin interaction sites associated with NPC, and found the chromosomal translocation and chromatin interaction sites associated with NPC based on statistical analysis. This study has certain guiding significance for in-depth study of the mechanism of NPC occurrence and development.