Aggregation-induced photoluminescence enhancement of protamine-templated gold nanoclusters for 1-hydroxypyrene detection using 9-hydroxyphenanthrene as a sensitizer.

In this study, we confirmed that protamine-templated gold nanoclusters (PRT-AuNCs) exhibit aggregation-induced emission properties (AIE-PRT-AuNCs). 1-Hydroxypyrene (1-OHPy) further induced the aggregation of AIE-PRT-AuNCs via hydrogen bonding and electrostatic and hydrophobic interactions, resulting in the aggregation-induced photoluminescence enhancement of AIE-PRT-AuNCs. 9-Hydroxyphenanthrene was able to decrease the background signal, thus increasing the sensitivity of the method. Based on these findings, a cost-effective, highly sensitive and selective strategy was proposed for the quantitative detection of 1-OHPy. This method displayed a wide linear range of 0.924 - 74.1 nmol/L with a low detection limit of 0.277 nmol/L, showing great potential for the monitoring of 1-OHPy in human urine. This strategy may provide a theoretical basis for future studies of the AIE properties of metal nanoclusters and their applications in the field of chemical and biological sensing.

Assay of 1-hydroxypyrene via aggregation-induced quenching of the fluorescence of protamine-modified gold nanoclusters and 9-hydroxyphenanthrene-based sensitization.

This work describes a method for the determination of 1-hydroxypyrene (OH-Py) via aggregation-induced quenching of the emission of protamine-coated gold nanoclusters using 9-hydroxyphenanthrene (OH-Phe) as a sensitizer to boost the emission efficiency of nanoprobe. Under optimum conditions, the drop in fluorescence intensity at excitation/emission wavelengths of 300/596 nm is proportional to the concentrations of OH-Py in the range from 1.0 to 65 nM. The relative standard deviations are 4.2, 2.4 and 1.9% (for n = 11) at concentration levels of 8.0, 32 and 48 nM of OH-Py, respectively. The detection limit is 0.3 nM which is much lower than that of some previously reported methods. The recoveries from urine samples spiked with OH-Py ranged between 94.4 and 98.8%. Graphical abstract 1-Hydroxypyrene (OH-Py) can trigger the aggregation of protamine-gold nanoclusters (PRT-AuNCs), resulting in the emission quenching of PRT-AuNCs. 9-Hydroxyphenanthrene (OH-Phe) can boost the emission efficiency of nanoprobe. Thereby, a highly sensitive assay of OH-Py was established.