analytical method over the past few decades, and holds great promise in various analytical application fields, especially in the analysis of biological samples. [1-3] By far, remarkable efforts have been made to develop various types of ECL based biosensing systems, [4,5] and the recent introduction of new ECL materials or mechanisms, such as metal-organic frameworks, aggregation-induced emission luminogens or single atom catalysts, further improved the performance and application ranges of ECL based biosensing systems. [6-11] However, as a method extremely sensitive to the state of the electrode surface, nonspecific adsorption of biological macromolecules, in particular proteins, and physical scratches of the electrode surfaces, during the sensing of complex biological samples, severely affects the accuracy and practical applicability of the ECL biosensing systems. [12] In order to meet the requirements of anti-interference and long-term application in practical biosensing applications, it is highly demanded to develop ECL biosensing systems with anti-biofouling and self-healing properties. Although some efforts have been made to enhance the anti-biofouling property of ECL biosensing systems, for example, the introduction of hydrophilic polymers or biopolymers to construct protein-resistant anti-fouling electrode surfaces, these methods still encounter the disadvantages such as poor conductivity and complicated synthesis procedures. [13-15] Furthermore, few studies worked on the development of ECL biosensing system exhibiting self-healing properties, or, even more, ECL sensing systems exhibiting anti-biofouling and selfhealing properties simultaneously. [16] Therefore, the construction of ECL biosensing systems exhibiting both antifouling and self-healing properties is highly desired and of great importance for practical biological applications. Hydrogels composed of 3D crosslinked hydrophilic polymer networks have gained much attention recently as building materials in the construction of electrochemical and ECL biosensing systems. [17] The highly porous structure of hydrogels allows the efficient immobilization of ECL probes, and also Electrochemiluminescence (ECL) showed great potential in various analytical applications, especially in the sensing of biotargets, taking advantage of its high sensitivity, selectivity, ease of spatial and temporal control, and simplified optical setup. However, during the sensing of complex biological samples, ECL sensors often suffered severe interferences from unavoidable nonspecific-binding of biomacromolecules and physical damages of ECL sensing interfaces. Herein, a hydrogel based ECL biosensing system exhibiting excellent anti-biofouling and self-healing properties is developed. A protein hydrogel composed of bovine serum albumin (BSA) directed fluorescent Au/Ag alloy nanoclusters (Au/Ag NCs) is applied in building ECL sensing systems. The hydrogel matrix facilitates the immobilization of fluorescent Au/Ag NCs as excellent ECL probes, and the porous hydrophilic structure a...

In addition to their roles as revolutionary genome engineering tools, CRISPR-Cas systems are also highly promising candidates in the construction of biosensing systems and diagnostic devices, which have attracted significant attention recently. However, the CRISPR-Cas system cannot be directly applied in the sensing of non-nucleic acid targets, and the needs of synthesizing and storing different vulnerable guide RNA for different targets also increase the application and storage costs of relevant biosensing systems, and therefore restrict their widespread applications. To tackle these barriers, in this work, a versatile CRISPR-Cas12a-based biosensing platform was developed through the introduction of an enzyme-free and robust DNA reaction network, the entropy-driven dynamic DNA network. By programming the sequences of the system, the entropy-driven catalysis-based dynamic DNA network can respond to different types of targets, such as nucleic acids or proteins, and then activate the CRISPR-Cas12a to generate amplified signals. As a proof of concept, both nucleic acid targets (a DNA target with random sequence, T, and an RNA target, microRNA-21 (miR-21)) and a non-nucleic acid target (a protein target, thrombin) were chosen as model analytes to address the feasibility of the designed sensing platform, with detection limits at the pM level for the nucleic acid analytes (7.4 pM for the DNA target T and 25.5 pM for miR-21) and 0.4 nM for thrombin. In addition, the detection of miR-21 or thrombin in human serum samples further demonstrated the applicability of the proposed biosensing platform in real sample analysis.

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