Low-Triggering-Potential Electrochemiluminescence from a Luminol Analogue Functionalized Semiconducting Polymer Dots for Imaging Detection of Blood Glucose

In recent years, semiconducting polymer dots (Pdots) as environmentally friendly and high-brightness electrochemiluminescence (ECL) nanoemitters have attracted intense attention in ECL biosensing and imaging. However, most of the available Pdots have a high ECL excitation potential in the aqueous phase (>1.0 V vs Ag/AgCI), which causes poor selectivity in actual sample detection. Therefore, it is particularly important to construct a simple and universal strategy to lower the trigger potential of Pdots. This work has realized the ECL emission of Pdots at low-trigger-potential based on the electrochemiluminescence resonance energy transfer (ERET) strategy. By covalently coupling the Pdots with a luminol analogue, N-(4-aminobutyl)-N-ethylisoluminol (ABET), the ABEI-Pdots showed an anodic ECL emission with a low onset potential of +0.34 V and a peak potential at +0.45 V (vs Ag/AgCI), which was the lowest trigger potential reported so far. We further explored this low-triggering-potential ECL for imaging detection of glucose in buffer and serum. By imaging the ABEI-Pdots-modified screen-printed electrodes (SPCE) at +0.45 V for 16 s, the ECL imaging method could quantify the glucose concentration in buffer from 10 to 200 mu M with detection limits of 3.3 mu M, while exhibiting excellent selectivity. When applied to real serum, the results of our method were highly consistent with a commercial blood glucose meter, with the relative errors ranging from 3.2 to 13%. This work provided a universal strategy for constructing low potential Pdots and demonstrated its application potential in complex biological sample analysis.

Automated summary

In recent years, semiconducting polymer dots (Pdots) have attracted intense attention in ECL biosensing and imaging as environmentally friendly and high-brightness nanoemitters. However, the high ECL excitation potential of most available Pdots in the aqueous phase leads to poor selectivity in sample detection. This work demonstrates a simple and universal strategy to lower the trigger potential of Pdots based on electrochemiluminescence resonance energy transfer (ERET). The low potential Pdots showed excellent performance in glucose imaging detection.