ZIF-8 for advanced biosensors: from synthesis strategies to sensing platforms, applications and structure-performance relationships

Zeolitic imidazolate framework-8 (ZIF-8), a well-known member of the metal-organic framework (MOF) family, has garnered considerable interest because of its remarkable biocompatibility, large surface area, chemical stability, and structural tunability. ZIF-8 and its derivatives are promising for sophisticated biosensing applications because of these characteristics. This review systematically examines recent advances in ZIF-8 based biosensors, covering ZIF-8 synthesis strategies from conventional to bioinspired and environmentally friendly approaches, including solvothermal/hydrothermal, mechanochemical, sonochemical, seed-assisted, and self-assembly methods. The resulting ZIF-8 structures and their roles in different sensing platforms are critically discussed, with particular attention to crystal size, framework defects, hierarchical porosity, surface modification, and composite interfaces that influence analyte transport, biomolecule retention, and signal generation. The review also examines the incorporation of ZIF-8 into electrochemical, fluorescence, colorimetric, electrochemiluminescent, and SERS-based biosensors, emphasizing its functions in signal amplification, improved selectivity, and biomolecule immobilization. Additionally, structure-performance relationships are further discussed for the detection of food contaminants, environmental pollutants, and biomolecules. Future opportunities for real-world applications and important issues like sensitivity, repeatability, stability in complex systems and commercialization of these sensors are discussed. Overall, this review provides a comprehensive perspective on ZIF-8 synthesis, sensing platforms, applications, and structure-performance relationships, supporting the rational development of next-generation ZIF-8 based biosensors.