Nanomaterials as signal amplification elements in aptamer-based electrochemiluminescent biosensors

Biosensor technology is experiencing an unprecedented momentum that is driven by rapid advances in material science for utilization in various fields, and is constantly evolving to develop fast, simple and sensitive sensors. Here, we present a comprehensive and concise review on electrochemiluminescent (ECL) nanomaterial-based aptasensors including challenges and applications. ECL aptasensor combines the merits of a biosensor, selectivity of an aptamer, and sensitivity of ECL to construct sensitive and selective sensors. Signal amplification processes through the incorporation of nanomaterials are essential to further enhance the sensitivity of ECL sensing systems. Nanomaterials are commonly utilized in sensor fabrication as (i) electrode modifiers, (ii) nanocarriers, (iii) nanocatalysts, and (iv) luminophores. The review highlights the effects of integrating nanomaterials such as gold nanoparticles, metal nanoparticles, metal oxides, carbon nanomaterials, metal organic frameworks, and quantum dots using various research strategies that address signal amplification to enhance the ECL signal. Furthermore, various concepts have been demonstrated with relevant figures and explanations to serve as a general overview for the design of ECL aptasensors. Lastly, we discuss the underlying problems and possibilities for ECL aptasensor research and development.