A novel colorimetric/fluorescent dual-signal probe based on silver nanoparticles functionalized with L-cysteine and rhodamine 6G derivatives for copper ion detection and cell imaging

The dual-signal probe utilizing functionalized silver nanoparticles (AgNPs) is a promising sensing tool. Herein, a novel colorimetric/fluorescent dual-signal probe (AgNPs-L-Cys-Rh6G2) was fabricated for copper ion (Cu2+) detection and cell imaging by using L-cysteine as a bridge to connect AgNPs and rhodamine 6G derivatives. The AgNPs-L-Cys-Rh6G2 probe exhibits a dual-signal response to Cu2+ due to Rh6G2 hydrolysis, resulting in a high fluorescence response and a significant change in color from light yellow to pink under sunlight. The linear detection ranges of the AgNPs-L-Cys-Rh6G2 probe for Cu2+ were 100-450 & mu;M and 150-650 & mu;M using fluorescent and colorimetry methods, respectively. The detection limits were as low as 0.169 & mu;M and 1.36 & mu;M, respectively. Meanwhile, the proposed probe was applied to detect Cu2+ in the actual sediment with satisfactory recovery and low relative standard deviation. Furthermore, the probe was further employed for fluorescence imaging in HeLa cells. In brief, the developed AgNPs-L-Cys-Rh6G2 sensing platform can be used for simultaneous Cu2+ determination and cell imaging.

Automated summary

A novel colorimetric/fluorescent dual-signal probe (AgNPs-L-Cys-Rh6G2) was developed for copper ion (Cu2+) detection and cell imaging using functionalized silver nanoparticles (AgNPs). The probe exhibited a dual-signal response to Cu2+ due to rhodamine 6G derivatives' hydrolysis, with high fluorescence response and significant color change. It had a linear detection range of 100-450 μM and 150-650 μM using fluorescent and colorimetry methods, respectively, with low detection limits of 0.169 μM and 1.36 μM. The probe also showed satisfactory recovery and low relative standard deviation for Cu2+ detection in actual sediment, and could be used for fluorescence imaging in HeLa cells.