Green emitting carbon dots-immunosensor on magnetic nanoparticles for detection of Nanog antigen as a cancer stem cell biomarker

Background

Embryonic Nanog is recognized as a crucial controller of pluripotency. In the progression of cancer and the formation of metastasis, cancer cells with stem cell-like characteristics frequently express Nanog. Precisely identifying the Nanog antigen poses a significant challenge due to its low abundance in biofluids. The precise detection of the Nanog antigen originating from cancer cells has attracted growing interest for its potential uses in diagnostics and prognostics.

Results

In this study, a novel fluorescence strategy utilizing green carbon dots was developed for the highly sensitive and specific detection of Nanog. This approach involved the use of fluoro-immunosensors based on magnetic nanoparticles (MNPs) and antibodies targeting the cancer Stem Cells (CSCs) biomarker, Nanog. In this study, the targeted Nanog was magnetically separated following its reaction with green carbon dots and magnetic nanoparticles, both conjugated with anti-nanog antibodies. The findings show a clear increase in fluorescence with the rising concentration of Nanog antigen in the sample. The linear range for Nanog, measured under optimal experimental conditions, was found to be 5.0 × 10 ⁻¹¹ g/L to 1.0 × 10 ⁻⁹ g/L. The detection limit (LOD) was calculated to be 1.0 × 10 ⁻¹¹ g/L.

Significance

This study introduces a fluoro-immunosensor employing magnetic nanoparticles (MNPs) and high quantum efficiency green-emitting carbon dots. This represents the first use of these carbon dots in this type of sensor. The biosensor has demonstrated effective detection of Nanog in biological samples. This developed biosensor, which is both convenient and highly sensitive, presents a significant opportunity for quantifying Nanog in biological research and clinical applications.