Highly selective detection of spermine in human urine via a nanometal surface energy transfer platform

Under acidic condition, spermine possessed multi-cationic property and a strong affinity towards the anionic phosphate backbone of calf thymus DNA (ctDNA) by electrostatic attraction and as well as the groove binding, which enabled the process of nanometal surface energy transfer (NSET) between gold nanorods and porphyrin, leading to the fluorescence quenching, which was proportional to the concentration of spermine. The NSET platform for spemine is simple, sensitive and time-saving, which has great significance in early cancer diagnosis.134