TRIPLE SIGNALING MODE CARBON DOTS-BASED BIODEGRADABLE MOLECULARLY IMPRINTED POLYMER AS MULTI-TASKING VISUAL SENSOR FOR RAPID AND ON-SITE MONITORING OF SILVER ION

摘要

The present work describes the fabrication of a low-cost, simple, and highly selective analytical method based on unique combination of fluorescent carbon dots (CDs) and molecularly imprinted polymers (MIPs) for sensitive visual detection of silver ion at trace level in real samples in both outdoors and at home-conditions. For the first time fluorescein dye was used as a precursor for the preparation of CDs. The prepared CDs possess less toxicity, high stability, good quantum yield and free-from the common problems (low stability, weak fluorescence intensity, and fast photo-bleaching) of commercially available dyes. The CDs modified MIP (Formula V, (CDs@MIP) was successfully applied for calligraphy and staining of 3-D crafted papers. In addition, the prepared Formula V (CDs@MIP) was very well explored to demonstrate the triple-signalling mode, trace-level detection of silver ions, in which a simple Formula V (CDs@MIP) solution was sufficient to monitor the presence of silver ions in real and complex matrices with naked eyes i.e. instrument-free analysis (detection limit = 10.0 μg L -1 ). However, the Formula V (CDs@MIP) modified filter-paper strips could be used for very handy, safe, sensitive, semi-quantitative and rapid detection of silver ion (response time 10 seconds). The silver ions present in real and complex samples (like human blood, urine, wastewater, silver cream and polymetallic ore) were easily analyzed and visually monitored by the strip as well as solution-phase Formula V (CDs@MIP) sensor. The prepared Formula V (CDs@MIP) shows negligible cytotoxicity towards MCF-7 cells, therefore, successfully explored for live cell imaging and intracellular analysis of silver ions. Therefore, the simple preparation, fast detection (10 seconds), low cost, easy-handling, layman operation strategy demonstrate that the proposed sensor have potential as practical and portable sensing interface for wide application in complex matrix analysis.