Non-conjugated polymer dots for fluorometric and colorimetric dual-mode detection of quercetin

•NCPDs was synthesized via environmentallyfriendly way.•Excellent optical properties and favorable stability of NCPDs were demonstrated.•Dual-mode method was proposed for quercetin detection.•The dual-mode strategy provided a simpler, more effective and more reliable way. Due to the biochemical and pharmacological activities, the convenient and effective detection of quercetin (Qc) is very important for biochemistry, pharmaceutical chemistry and clinical medicine. A kind of non-conjugated polymer dots (NCPDs) was used as a versatile and sensitive dual-mode optical output for Qc detection, which was synthesized by hyperbranched poly(ethylenimine) (PEI) and l-threonine via environmentallyfriendly way. The dual-mode method proposed in this work had high sensitivity and definiteselectivity for Qc detection. Additionally, it was convenient for the naked eyes to observe the fluorescence brightness and color change.