Fluorescence nanoprobes bearing low temperature-derived biochar nanoparticles as efficient quenchers for the detection of single-stranded DNA and 17β-estradiol and their analytical potential.

Bagasse-derived biochar nanoparticles obtained under a low pyrolysis condition (400 °C) were first revealed to be capable of highly efficiently quenching the fluorescence of 6-carboxyfluorescein, with a significantly improved quenching rate constant over that of other quenchers and high-temperature prepared ones, and were designated as bagasse-derived quencher nanoparticles (BQNPs). The BQNPs are suitable for the construction of fluorescence nanoprobes, taking advantage of their various beneficial properties, including low cost, environmental friendliness, high dispersibility, and rich functional groups that allow their easy and versatile molecular modification. They were demonstrated to be capable of stably binding single-stranded oligonucleotides through both adsorption and covalent interactions and were utilized for the construction of both BQNPs/DNA and BQNPs/aptamer probes.