InSitu-Grown Cdot-Wrapped Boehmite Nanoparticles for Cr(VI) Sensing in Wastewater and a Theoretical Probe for Chromium-Induced Carcinogen Detection

Abstract

In modern society, massive industrialization escalates environmental degradation by liberating various contaminants into the environment. Hexavalent chromium is a heavy metal that is being discharged from tannery and other industries, resulting in various carcinogenic diseases. This study reports a carbon dot (cdot)-based fluorometric probe for detecting hexavalent chromium in water. This is the very first time that cdots are tailored over the boehmite nanoparticle's surface using an in situ approach. Validation of formation of the nanocomposite has been discussed in detail employing the Rietveld refinement-based X-ray crystallography method. Vibrational spectroscopy and electron microscopy of the sample authenticate the nucleation process and the growth mechanism. The Stern−Volmer approach and time-resolved fluorescence measurements justify the sensitivity of the sensor (∼58 nM), and selectivity is analyzed by exposing the material to different ionic environments. Density functional theory (DFT) is applied herein to analyze the origin of fluorescence and the sensing mechanism of the probe, which shows that photoinduced electron transfer is responsible for the turn-off-based sensing of Cr(VI). The molecular docking simulation is carried out to ensure the binding of cdots to the binding pocket of the glutathione enzyme, which is responsible for treating reactive oxygen species-mediated DNA damage due to elements such as hexavalent chromium. Time-dependent density functional calculations show that the fluorometric probe is capable of detecting Cr(VI) in living cells making it an early stage chromium-mediated carcinogen detector.

Biocompatible carbon dot decorated α-FeOOH nanohybrid for an effective fluorometric sensing of Cr (VI) in wastewater and living cells

“…Thus, no emission occurs during the LUMO-HOMO transition of the uorophores due to insu cient number of electrons. This phenomenon has been reported by various other groups in their recent papers [11].…”

“…While, the absorption bands at 520 and 675 cm − 1 are attributed to the Fe-CO and Fe-O symmetric stretching vibrations [26][27]. The vibration maxima between 774 and 900 and 1635 cm − 1 are ascribed to the O-H bending suggesting the adsorbed moisture and presence of CONH vibrations respectively in the sample [27,28] A small vibration centred at 1525 cm − 1 is assigned to the N-H bending arising from the nitrogenous carbon quantum dots [11].…”

“…Thus, there is a pressing need of restrict such agglomeration for better uorometric applications. There are earlier reports on C-dot immobilized on oxyhydroxides and mesoporous silica like matrices for sensing, [11] but those matrices are way too toxic to handle as they can diffuse through skin and pulmonary routes [12][13][14]. FeOOH nanoparticles has been approved and used widely as food and iron supplements [15,16] thereby its biosafe property make it advantageous in employing it as heavy metal ion sensor.…”

Metal-Ion-Cross-Linked Nitrogen-Doped Carbon Dot Hydrogels for Dual-Spectral Detection and Extractable Removal of Divalent Heavy Metal Ions

“…Among the many methods for detecting heavy metal ions, − fluorescence detection is a relatively new approach attracting more and more attention due to its high sensitivity and simple process. ,− Generally, a fluorescent probe can “perceive” target molecules either by adjusting its fluorescence intensity or by converting its emitting color. , New rich nanomaterials such as perovskite quantum dots, metal-organic framework (MOF) materials, and two-dimensional layered nanomaterials are attracting widespread attention due to their ultra-small size, selectivity, and promising fluorescence properties. ,, However, their wide range of applications was restricted due to the limitation of inconvenient synthesis, high cost, and poor stability. Carbon dots (CDs) are a type of emerging nanomaterial with striking and interesting fluorescence properties. ,− The CDs can sensitively “perceive” the target due to the rich dangling bonds on the surface.…”

“…Carbon dots (CDs) are a type of emerging nanomaterial with striking and interesting fluorescence properties. ,− The CDs can sensitively “perceive” the target due to the rich dangling bonds on the surface. What is more, CDs are becoming a potential candidate for various sensing applications because of their stable fluorescence emission, convenient synthesis methods, low cost, and excellent biocompatibility. ,, …”