Versatile NiCo2O4 nanosheets hybrids-based label-free immunosensor for thyroglobulin using photothermal amplification

Herein, an ultrasensitive label-free electrochemiluminescence (ECL) immunosensor based on electrocatalytic and photothermal amplification was constructed and was applied to detect Thyroglobulin (Tg). Single-walled carbon nanotube (SWCNTs) with charming merits was used as supporter for porous NiCo 2 O 4 nanosheets (pNiCo 2 O 4 NSs), the formed pNiCo 2 O 4 NSs/SWCNTs hybrids was utilized as an effective matrix and realized multiple signal amplification. To be specific, pNiCo 2 O 4 NSs/SWCNTs hybrids on the one hand can facilitate the electron transfer and enhance ECL signal. On the other hand can catalyze the oxygen evolution reaction (OER) to increase the concentration of dissolved O 2 for further strengthening ECL signal. What’s more, the pNiCo 2 O 4 NSs/SWCNTs hybrids had a strong near-infrared harvesting capability, can convert laser energy into heat to increase the electrode surface temperature, resulting in the significant enhancement in ECL signal. Based on excellent properties of pNiCo 2 O 4 NSs/SWCNTs hybrids, a highly-efficient label-free ECL immunosensor was developed and exhibited a wide linear range (10 −5  ng/mL to 100 ng/mL) and a low detection limit (3.3 × 10 −6  ng/mL) for Tg determination, which was approximately 7.1 fold-lower than at room temperature . This work provided a new thought for high-performance ECL sensing platform construction.