08-12-2021-0222 - Carbon quantum dots for the detection of antibiotics and pesticides

Carbon quantum dots for the detection of antibiotics and pesticides


Carbon quantum dots for the detection of antibiotics and pesticides

Han-Wei Chu a, Binesh Unnikrishnan a, Anisha Anand a, Yang-Wei Lin b, Chih-Ching Huang a,c,d,*

a Department of Bioscience and Biotechnology, National Taiwan Ocean University, Keelung, 20224, Taiwan b Department of Chemistry, National Changhua University of Education, Changhua City, 50007, Taiwan
c Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung, 20224, Taiwan
d School of Pharmacy, College of Pharmacy, Kaohsiung Medical University, Kaohsiung, 80708, Taiwan

Abstract

Carbon quantum dots (CQDs) are novel nanomaterials with interesting physical and chemical properties, which are intensely studied only in the last decade. Unique properties, such as its inherent fluorescent property, high resistance to photobleaching, high surface area, ease of synthesis, flexible choice of precursor, and surface tunability enable CQDs for promising application in biosensing. Therefore, it is highly useful in clinical, forensic, medical, food and drug analyses, disease diagnosis, and various other fields of biosensing. In addition, their fluorescence properties are tunable by the interaction with certain molecules via different mechanisms, which enables their application for sensing of those molecules, such as pesticides and antibiotics. The detection of antibiotics and pesticides is especially important as they are commonly used in both the medical and agricultural fields and can affect both humans and their environment. However, these molecules do not have a specific recognition element unlike for antibodies, proteins, enzymes, and other biomarkers. Thus, the fluorescence quenching mechanism alone cannot be applied as a sensing mechanism for the CQDs-based sensing of pesticides and antibiotics. In this review, we discuss the application of various CQDs, in the detection of antibiotics, pesticides (herbicide, fungicide, insecticide), and other medicinal drugs through various detection strategies and their current limitations.

Keywords: Carbon quantum dots, Fluorescence, Sensors, Agricultural chemicals, Medicinal drugs, Environment




Examples include oligonucleotides (electrostatic, hydrogen bonding, and p-p stacking interaction), proteins (electrostatic, hydrogen bonding, and hydrophobic interaction), and metal ions (hard-soft acid-base (HSAB) in- teractions).




Monitoring excessive antibiotic use whether in patients, animals or environment can be significant to understand and monitor the appearance of antibiotic resistance bacteria preva- lent in the region [12‒14]. It is not only antibiotic abuse in human medical settings that cause the development of drug resistance in bacteria, veteri- nary abuse of antibiotics is also a major derivation. Some even estimated that 80% of total antibiotics sold in the US are for veterinary use including those preemptively used on farm animals and live stocks [14]. Inherent toxicity of the antibiotics can also be a serious environmental hazard as several antibiotics are known to disrupt plant protein synthesis [14]. Screening for pesticides (including fungicide, insecticide, and herbicide) in the environment or on food products are also extremely crucial for human health, as consumption of pesticides can lead to or risk serious issues such as acute pesticide poisoning, Parkinson's disease, Alzheimer's disease, increase attention deficit hyperactivity disorder (ADHD) for children [15‒17].


As a result, the electrons are unable to traverse its original path (electron dropped from the lowest unoccupied molecular orbital (LUMO) to the highest occupied molecular orbital (HOMO) of the CQDs) and are forced to traverse a new path.


Other noncontact mechanisms such as the inner filter effect (IFE), fluorescence and chemiluminescence resonance energy transfer (FRET and CRET) can also be used in the detection of many analytes (Scheme 1).


The fluorescence of CQDs is enhanced when it interacts with amoxicillin with only very minor fluctuations in the presence of other interfering compounds such as glucose, sucrose, tryptophan, ascorbic acid, aspartic acid, L-cysteine, NaF, Ca(NO3)2 and KBr. The CQDs prepared from beet with a size of 6 nm can also be used for the detection of norfloxacin [48].


Nitrogen-doped CQDs (NCQDs) prepared from durian shell waste with Tris base as a doping agent, by a hydrothermal method is reported to be highly selective toward the detection of tetracycline with a LOD of 75 nM [49].


The fluorescence of CQDs is enhanced when it interacts with amoxicillin with only very minor fluctuations in the presence of other interfering compounds such as glucose, sucrose, tryptophan, ascorbic acid, aspartic acid, L-cysteine, NaF, Ca(NO3)2 and KBr.


In the presence of tetracycline, fluorescence quenching of the NCDs occurs due to IFE. Recently, Guo et al. have reported the detection of tetracycline using fluorescent CQDs obtained by the thermal cracking of crab shell waste [50]. With an average size of 10 nm and 30% fluorescent quantum yield, the highly stable CQDs could detect tetracycline with a LOD 5 mg L
1.


p-dihydroxybenzene and hydrazine hydrate CQD in the presence of Fe3+


Glutathione and polyethylenimine -

Citric acid -
Rice residue Nitrogen doped CQD


Citric acid and L-cysteine Sulfur- and nitrogen- doped CQD b-cyclodextrin functionalized N,Zn-codoped CQD

Ethylenediamine


Fungus fiber Nitrogen, sulfur dual doped CQD


Glutamic acid



Citric acid formamide -


Citric acid and urea Piperizine modified- CQD


Citric acid and ethylene diamine/citric acid
and urea p-phenylenediamine and acetic acid Nitrogen-rich CQD


Europium nitrate hexahydrate and Europium-doped CQD

citric acid monohydrate

Durian shell waste Nitrogen-doped CQD


Dried beet powder


Crab shell waste Nitrogen-rich CQD


Oxytetracycline and norfloxacin Kanamycin Tetracycline, terramycin, chlortetracycline Oxytetracycline Ofloxacin Amoxicillin Ampicillin Chlortetracycline


Au NCs quenches the fluorescence of the N- doped CQDs through the FRET mechanism; how- ever, when carbendazim is introduced, it interacts with the Au NCs and the CQDs remain free and the fluorescence is recovered.




The H2O2 produced by the acetylcholines- terase/choline oxidase system quenches the fluo- rescence of GQDs, however, in the presence of organophosphate pesticides, the enzymatic activity is inhibited, and the fluorescence of the GQDs is retained.

https://www.jfda-online.com/cgi/viewcontent.cgi?article=1269&context=journal







Reference


Chu, Han-Wei; Unnikrishnan, Binesh; Anand, Anisha; Lin, Yang-Wei; and Huang, Chih-Ching (2020) "Carbon

quantum dots for the detection of antibiotics and pesticides," Journal of Food and Drug Analysis: Vol. 28 : Iss. 4 , Article 5.
Available at: https://doi.org/10.38212/2224-6614.1269