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• An amorphous P-doped bimetallic NiCo-MOF was prepared as a precursor material. • A di-heteroatom doped heterogeneous Ni-Co hybrid material (P-NiCoS@C) with amorphous structure was synthesized for HSC device. • 3. The P-NiCoS@C electrode exhibits a high specific capacity of 1168.2 C g−2 at 1 A g−1. • 4. The assembled P-NiCoS@C//AC HSC device can achieves the high energy density with the excellent cyclic performance. Amorphous electrode materials can have some unique advantages for supercapacitors. Herein, P and S di-heteroatom doped heterogeneous Ni-Co hybrid nanomaterial (P-NiCoS@C) with an amorphous structure is designed and used as the positive electrode material for hybrid supercapacitor (HSC). The amorphous P-NiCoS@C nanomaterials are synthesized using amorphous P-doped NiCo-MOF as the sacrificial template, followed by a thermal treatment process to simultaneously complete carbonization and S doping. The unique nanoparticle structure provides a large specific surface area, abundant reactive sites and high redox activity. As an electrode material, P-NiCoS@C exhibits superior electrochemical performance, with a specific capacity of 1168.2 C g−1 at 1 A g−1. Moreover, the assembled P-NiCoS@C//activated carbon HSC device can output a high energy density of 55.8 Wh kg−1 at a power density of 800.0 W kg−1, and retained 75.7% of the initial performance after 10,000 cycles. This research provides a new perspective for obtaining electrode materials with high charge storage performance. Graphical Abstract. [Display omitted]. [ABSTRACT FROM AUTHOR]

Metal organic frameworks (MOFs) are an ideal platform to construct electroactive materials for electrochemical energy storage due to their unique structure and excellent porosity. However, it is still a challenge to make full use of their structural advantages to rationally design multi-component electrode materials for high-performance supercapacitors. Herein, carbon-coated spherical sulfide nanoparticles are reported by simultaneous carbonization and sulfurization using bimetal/monometal-based MOFs as the precursors. The NiCo 2 S 4 @C and NiS@C composite nanoparticles have excellent electronic conductivity, large porosity and high electrochemical reaction activity. In particular, the bimetallic NiCo 2 S 4 @C-based electrode exhibits a high specific capacity of 948.9 C g−1 at 1 A g−1. Furthermore, a hybrid supercapacitor assembled with NiCo 2 S 4 @C as the positive electrode and activated carbon as the negative electrode achieves a high energy density of 43.8 Wh kg−1 with power density at 799.1 W kg−1, and a capacitance retention rate of 81.9% after being subjected to 5000 cycles of charge and discharge. The results suggests using MOFs as precursors is a feasible strategy to synthesize advanced sulfide-based multi-component materials for electrochemical energy storage. [Display omitted] [ABSTRACT FROM AUTHOR]

• Carbonized polymer dots were first used as ECL luminophores. • Cathodic carbon-based ECL excitation potential as low as -0.95 V for the first time. • The nanoconfinement enhancement of ZIF-8 significantly augments the ECL response. • Fe 3 O 4 as a co-reaction accelerator involved in the redox reaction remarkably boosted the ECL signal. • The established immunosensor exhibited a low detection limit of 126 fg/mL for CYFRA21–1. Developing novel luminophores for electrochemiluminescence (ECL) that could operate smoothly under low-potential excitation while incorporating creative enhancement strategies is a challenging but very attractive initiative to achieve sensitive detection of disease markers. Herein, carbonized polymer dots (L-CPDs) with low cathode excitation potential were successfully synthesized and used for dual amplified sensitive electrochemiluminescence immunoassay of cytokeratin 19 fragment antigen 21–1 (CYFRA21–1). l -CPDs were first used as ECL luminophores and have an unprecedentedly low excitation potential of -0.95 V that has not been equipped for other cathodic carbon-base dots, avoiding side reactions, bioactive damage and electrode polarization due to high potential, thus obtaining excellent sensor performance. In addition, zeolitic imidazolate framework-8 (ZIF-8) synthesized at room temperature as a nanoconfinement carrier encapsulated l -CPDs and reduced the non-radiative energy loss of the luminophore, which led to substantially improved the ECL signal. The ECL efficiency of the encapsulated luminophores is 2.7 times higher than that of monomeric l -CPDs at the same mass concentration. Platinum composite iron oxide (Fe 3 O 4 /Pt) was used as a co-reaction acceleration platform to strengthen the ECL response. The sandwich ECL immunosensor fabricated achieved sensitive detection of CYFRA21–1 in the detection range of 150 fg/mL–110 ng/mL with a detection limit of 126 fg/mL. In conclusion, this work provides a consideration direction of developing ideal luminophores complemented by amplification strategies in ECL systems construction to achieve accurate and sensitive detection of targets. [Display omitted] [ABSTRACT FROM AUTHOR]

• CePO 4 @Au was introduced into the ECL immunosensor for the first time, which significantly improved the electrochemiluminescence intensity of the NHCDs-H 2 O 2 system. • CePO 4 @Au can promote the decomposition of H 2 O 2 to produce O 2 •−, the repeated conversion of Ce4+ and Ce3+ has high electrocatalysis activity, which can facilitate the production of O 2 •−. • BaTiO 3 @Ag was used as a carrier to accurately capture NHCDs and anchor antibodies to provide a stable ECL signal. • The established ECL immunosensor exhibited low detection limit of 9.55 fg/mL for AFB1. In various detection methods of aflatoxin B1 (AFB1), false positives and false negatives are common due to the low sensitivity, expensive equipment or improper pretreatment during operation. Here, a sandwich electrochemiluminescence (ECL) immunosensor armed with a synergistic co-reaction acceleration strategy was employed for the ultra-sensitive detection of AFB1. Benefiting from the catalytic properties of Ce3+/Ce4+ redox pairs, cerium phosphate@gold (CePO 4 @Au), for the first time, was introduced into the immunosensor as a new type of co-reaction accelerator, and it significantly improved the ECL intensity of the nitrogen doped hydrazide conjugated carbon dots (NHCDs)-H 2 O 2 system. CePO 4 @Au has the ability to promote the decomposition of H 2 O 2 and accelerate the formation of O 2 •−. The more of O 2 •− reacts with NHCDs to produce a stronger and more robust ECL signal response. Furthermore, the spindle-shaped sensing interface formed by oxidation cerium and phosphate has a high loading area and good biocompatibility, and the modification of Au nanoparticles further achieves the stable binding of the capture antibody. Striving for further improvement, Ag modifies Barium titanate (BaTiO 3), as the signal carrier with amplification ability, loads with a large number of anodic luminescent carbon quantum dots, were adopted as detection markers for the construction of sandwich ECL biosensors. The co-reaction amplification system achieves high precision quantitative detection of AFB1 in the linear range of 0.01 pg/mL–100 ng/mL, and the detection limit is 9.55 fg/mL. In addition, the constructed biosensor also showed good stability, reproducibility and specificity, with a promising application prospect. [ABSTRACT FROM AUTHOR]