Dual noncovalent interaction facilitated highly sensitive and specific colorimetric–fluorescent sensing for tryptamines

Abstract

Tryptamines, an important family of new psychoactive substances, have attracted special attention from the international community owing to their abuse and corresponding influence on human health and social stabilization. However, realizing the on-site analysis of tryptamines with rapid and precise responses remains a great challenge, especially if these are present in their disguised form. A highly sensitive and specific analytical method was developed herein, driven by a dual noncovalent interaction towards tryptamines. An optical probe was designed to specifically recognize tryptamines via π–π stacking and hydrogen bond effect to produce significant optical responses for both colorimetric and fluorescent modes. The detection limits were calculated as 4.1 nM (fluorescent mode) and 17.2 μM (colorimetric mode), respectively, with an excellent specificity towards 16 interfering substances within 0.6 s. Based on the excellent detection performances of the proposed probe, a portable and operable sensor was developed and demonstrated with the rapid and accurate analysis capability towards the controlled α-methyl-tryptamine in complicated scenarios. We expect the portable sensor equipped with this optical probe would provide a powerful tool for trace tryptamine detection and effective technical support for real-time monitoring of other new psychoactive substances in complicated media.