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.

Novel nanocomposite of spiky-shaped gold nanourchins/ titanium dioxide/nafion for amplified signal and efficient electrochemiluminescence detection of ovomucoid.

This work reports on the first electrochemiluminescence (ECL) immunosensor employing a novel nanostructured composite of titanium dioxide (TiO2) and gold nanourchins (AuNU) to detect protein allergen Ovomucoid (Ovm) found in eggs. TiO2 and AuNU were dispersed in Nafion and drop-casted onto SPGE with Tris(2,2'-bipyridyl)-ruthenium (II) ([Ru(bpy)3]2+) and tri-n-propylamine (TPrA) served as strong luminophore/co-reactant pairs as a source of ECL signals. The linear range, limit of detection, reproducibility and practical applications of the sensor were assessed. The fabricated ECL immuosensor produced a promising limit of detection of as low as 0.01 pg/mL. Two linear ranges of 0.01-50 pg/mL and 100-750 pg/mL with corresponding correlation coefficients of R2 = 0.99136 and R2 = 0.97829) respectively, were determined. Despite its simple fabrication method, this label-free immunosensor also showcased excellent selectivity, reproducibility, interference-resistance and yielded outstanding recoveries between 97.42 and 104.05% of Ovm analysis in spiked real food samples.