Translation of Carbon Dot Biosensors into an Embedded Optical Setup for Spoilage and Adulteration Detection

Abstract

This research demonstrates a carbon quantum dot (CQD) based fluorescence technique for milk quality assessment and detection of urea adulteration using a commercialized optical fiber spectrometer (OFS) and a developed color sensor device (CSD). The change in pH from the normal pH of milk (∼6.7) indicates spoilage. The CQDs were synthesized using phthalic acid (carbon source) and triethylenediamine (TED) (passivant). The CQDs were found to be sensitive in the pH range 3−10 with a quantum yield of about 18.9%. The accuracy of spoilage detection using CQDs was expressed in the form of mean percent recovery and found to be 99.2% (R 2 = 0.97) by the OFS and 99.59% (R 2 = 0.98) by the CSD. The mean percent recovery obtained for urea adulteration in milk was 103.0% (R 2 = 0.98) by the OFS and 97.9% (R 2 = 0.97) by the CSD. The results indicate that CQDs have excellent potential for use as biosensors for spoilage and adulteration detection.

Boosting Food System Sustainability through Intelligent Packaging: Application of Biodegradable Freshness Indicators

“…A portable sensing platform constructed by combining the indicator with a smartphone was used to determine the freshness levels of fish products under ultraviolet light. In another study, phthalic acid and triethylenediamine were used to prepare CDs that can be added in milk to detect freshness relying on the change in fluorescence intensity . The freshness of milk decreased with an increase in acidity, which could reduce the fluorescence intensity of CDs due to the protonation of carboxylic groups.…”

“…In another study, phthalic acid and triethylenediamine were used to prepare CDs that can be added in milk to detect freshness relying on the change in fluorescence intensity. 122 The freshness of milk decreased with an increase in acidity, which could reduce the fluorescence intensity of CDs due to the protonation of carboxylic groups. Although fluorescent nanomaterials have been used to develop novel freshness indicators, their applications in the food industry are limited due to their uncertain toxicity.…”

In Vivo and In Vitro Biodistribution of Inulin-Tethered Boron-Doped Amine-Functionalized Carbon Dots

“…Carbon dots (CDs), a promising family of fluorescent nanomaterials, have sparked a lot of interest over the past decade. , CDs have optical characteristics that differentiate them from inorganic quantum dots . Fluorescent CDs offer numerous benefits over other fluorescent nanomaterials, including appropriate dimensions and/or excitation wavelength-dependent photoluminescence (PL), photostability, facile surface modification, low cytotoxicity, and a variety of synthesis processes. − Thus, fluorescent carbon dots have piqued the interest of researchers in a wide range of biomedical applications, comprising biological assays, , bioimaging, , cell labeling, , biosensors, , disease detection, , and drug delivery. , Typically, the two basic operating procedures that make the chemical, optical, and electrical properties of CDs adjustable and controlled are element doping and surface functionalization …”

Fluorescent fiber-optic device sensor based on carbon quantum dot (CQD) thin films for dye detection in water resources

“…QDs can also undergo a variety of mechanisms such as fluorescence resonance energy transfer (FRET), fluorescence, energy transfer, luminescence, photocurrent generation, etc. [26][27][28] Carbon quantum dots (CQDs) have additional advantageous properties such as biocompatibility, biological tunability, non-toxicity, cost effectiveness etc. With these additional properties CQDs are capable of being used in various biological applications where the biggest concern is toxicity.…”