Nanosponges for Chemosensors and Biosensors: Next Generation Functional Materials

Nanosponges (NSPs), a class of porous, tunable, and high-surface-area materials, have emerged as next-generation platforms for chemo- and bio-sensing applications, enabling enhanced detection sensitivity, selectivity, and real-time responsiveness. Their unique architecture, engineered through metal-based, metal-oxide, and hybrid frameworks, offers controlled porosity, flexibility in functionalization, and high analyte-binding affinity. Over the past decade, NSPs have been progressively integrated into optical, electrochemical, and enzymatic sensor systems, targeting environmental toxins, toxic gases, metal ions, and biological markers. This review systematically discusses the structural fundamentals of NSPs, including polymeric backbones, crosslinking chemistry, and active sites responsible for molecular recognition. A critical analysis of NSP functionalization strategies, fabrication factors, and performance limitations is presented to guide material optimization. Applications are explored across chemosensing (heavy metal ion detection, toxic gas analysis) and biosensing (glucose, enzyme activity, and pathogen identification), highlighting the integration of NSPs into field-deployable diagnostic platforms. Furthermore, the review outlines the key challenges in NSP-based sensor technology, such as stability, reusability, and multiplexed detection, and provides a future outlook on their role in intelligent, miniaturized, and sustainable sensing devices for environmental and healthcare diagnostics.