Fluorescent carbon dots (C-dots) have possessed remarkable and intricate properties which raised concerns and curiosity among researchers in their synthetic aspect. In this outlook, the current work reported the scale-up synthetic protocol for transforming agarose waste, a biologically infectious environmental contaminant, into highly fluorescent C-dots. The formed particles have better control over size, optical and luminescence properties. The value of quantum yield for the developed C-dots was found to be 62%. The detailed mechanistic insight into their optical and solvatochromic behaviour in presence of commercially used solvents has enhanced the knowledge and providing proper justification behind the optical changes in C-dots due to solvation effects. The toxicological screening via multiple assay approach has further attributed towards their biocompatible nature as function of concentration range from 100–5000 ppm. The suggested “waste-to wealth” stratagem is a prosperous step towards tough chore of multiple ion detection of Zn${}^{2+}$ and ${{\mathrm{CO}}_3}^{2-}$ ions from aqueous media. The fluorescence enhancement analysis has enumerated the concentration dependency in the range of 50 $\mathrm{\mu }$M to 30 nM and 10 $\mathrm{\mu }$M to 60 nM with detection limit value of 0.26 nM and 0.17 nM for Zn${}^{2+}$ and ${{\mathrm{CO}}_3}^{2-}$ ions, respectively. The current work provides the way for greener, cost effective and scaled up synthesis of toxicologically screened C-dots for dual fluorescent sensing and opened up the new horizons in environmental remediation applications.

荧光碳点（C-dots）具有非凡而复杂的特性，这引起了研究人员在合成方面的关注和好奇。在这种前景下，目前的工作报道了将合成琼脂糖废物（一种具有生物传染性的环境污染物）转化为高荧光C点的放大合成方案。形成的颗粒对尺寸，光学和发光性质具有更好的控制。发现所形成的C-点的量子产率为62％。在存在商用溶剂的情况下对其光学和溶剂变色行为的详细机理研究增强了知识，并为由于溶剂化效应而引起的C点光学变化提供了合理的依据。通过多种测定方法进行的毒理学筛选进一步归因于其生物相容性，其浓度范围为100-5000 ppm。所建议的“从废物转化为财富”战略是迈向繁杂的锌多离子检测的艰巨步骤${}^{2+}$ 和 ${{\mathrm{一氧化碳}}_3}^{2-}$水性介质中的离子。荧光增强分析已列举出浓度依赖性在50$\mathrm{\mu }$M至30 nM和10 $\mathrm{\mu }$M至60 nM，Zn的检测极限值为0.26 nM和0.17 nM${}^{2+}$ 和 ${{\mathrm{一氧化碳}}_3}^{2-}$离子。当前的工作提供了一种绿色环保，具有成本效益的方法，并扩大了用于双荧光传感的经毒理学筛选的C-点的合成，并为环境修复应用开辟了新领域。