Gold nanoparticle–based colorimetric aptasensor for rapid detection of six organophosphorous pesticides

Bai, Wei; Zhu, Chao; Liu, Jinchuan; Yan, Mengmeng; Yang, Shi‐Yao; Chen, Ailiang

doi:10.1002/etc.3088

Cited by 94 publications

(45 citation statements)

References 48 publications

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“…Aggregation of AuNPs causes a shift in the absorbance peak to 630 nm and change in colour from wine red to blue. Aflatoxin M1 specific aptamers were adsorbed onto the surface of AuNPs by physiosorption between Au and N atom in DNA base 9 . It was observed that aptamer coated AuNPs were protected against salt aggregation.…”

Section: Resultsmentioning

confidence: 99%

Fabrication of microfluidic device for Aflatoxin M1 detection in milk samples with specific aptamers

Kasoju

Shahdeo

Khan

et al. 2020

Sci Rep

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This study describes the colorimetric detection of aflatoxin M1 (Afl M1) in milk samples using a microfluidic paper-based analytical device (µPAD). Fabrication of µPADs was done using a simple and quick approach. Each μPAD contained a detection zone and a sample zone interconnected by microchannels. The colorimetric assay was developed using unmodified AuNPs as a probe and 21-mer aptamer as a recognition molecule. The free aptamers were adsorbed onto the surface of AuNPs in absence of Afl M1, even at high salt concentrations. The salt induced aggregation of specific aptamers occurred in presence of Afl M1. Under optimum conditions, the analytical linear range was found to be 1 µM to 1 pM with limit of detection 3 pM and 10 nM in standard buffer and spiked milk samples respectively. The proposed aptamer based colorimetric assay was repeatable, quick, selective, and can be used for on-site detection of other toxins in milk and meat samples. Mycotoxins are secondary metabolites produced by filamentous fungi belonging to the genera Aspergillus and Penicillium 1. Mycotoxins are also found in animal derived foods such as milk due to intake of contaminated feed 2,3. Considering agricultural and economical aspects and possible implications on public health, the most relevant mycotoxins are aflatoxins, ochratoxins, fuminosins, T-2 toxin, and zearalenone (ZEA) 4. Aflatoxins pose a huge economic burden as they cause around 25% or more loss of the world's food crops every year 5. Afl M1 (4-hydroxy aflatoxin B1) and M2 (4-dihydroxy aflatoxin B1) have well proven carcinogenic and mutagenic potentiality and pose severe health consequences on milk consumers, including the risk of cancer and stunted growth in children below the age of 5 years 6. When B1 is ingested by a cow, it is secreted as hydroxylated metabolite aflatoxin M1 (Afl M1) in the urine and milk of the cow 7. Consumption of food containing aflatoxin concentrations of one milligram/kilogram or higher has been suspected to cause aflatoxicosis 8 , the prognosis of which consists of acute liver failure, jaundice, lethargy, and nausea, eventually leading to death within 1 to 2 weeks, based on past reports 9. Thus there is a need to develop rapid low cost technology based highly specific methods for detection of aflatoxins to improve surveillance and control in rural areas. A plethora of analytical techniques are available for aflatoxin M1 detection, ranging from chromatography and HPLC-MS used for regulatory control in official laboratories to rapid test kits for grain silos and farmers, especially for surveys when outbreaks occur 10,11. Conventional techniques for the detection of aflatoxins include gas chromatography (GC), fluorescence or UV based detection, thin layer chromatography (TLC) and enzyme linked immunosorbent assay (ELISA) 6-12. These techniques are routinely used and yield reliable results, however they are expensive, time consuming, require large scale instrumentation and large amounts of hazardous chemical reagents. Advancement in the development of bios...

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Section: Resultsmentioning

confidence: 99%

Fabrication of microfluidic device for Aflatoxin M1 detection in milk samples with specific aptamers

Kasoju

Shahdeo

Khan

et al. 2020

Sci Rep

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“…Other dangerous pesticides have been detected using AuNP-based colorimetric aptasensors [24]. The sensing mechanism is summarized in Figure 11.…”

Section: Mechanism Of Positive Charge Generation Upon Reaction Of Dcnmentioning

confidence: 99%

Red or Blue? Gold Nanoparticles in Colorimetric Sensing

Gaviña¹,

Parra²,

Gil³

et al. 2019

Gold Nanoparticles - Reaching New Heights

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Gold nanoparticles (AuNPs) have been extensively used for the design of colorimetric sensors and probes due to their interesting photophysical properties. In particular, their surface plasmon resonance (SPR) is influenced not only by the size but also by the shape or the properties of the matrix surrounding the nanoparticles. This SPR band is sensitive to the proximity of other nanoparticles, and thus, analyte-triggered aggregation of AuNPs results in an important bathochromic shift of the SPR band and a change in the color of the solution from red to blue due to interparticle surface plasmon coupling. The selectivity of the AuNPs-based sensors toward the different analytes will depend on the recognition properties of the molecules attached to the surface of the nanoparticles. In this chapter, a selection of biologically active molecules has been considered as analytes: neurotransmitters, nerve agents, pesticides, and carboxylates of biological interest.

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“…61 Aptamers can be incorporated into a AuNP-based sensor as the molecular recognition element. Thiol modified aptamers can be covalently bound to AuNPs 62,63 through the thiol sulfur and gold surface, or unmodified aptamers can be adsorbed [64][65][66][67] onto the surface of the nanoparticle. Based on the covalent or non-specific interaction between aptamers and AuNPs, a number of different aptamer based AuNP sensors have been developed for a variety of targets, including small molecules.…”

Section: Aptamer-based Gold Nanoparticle Biosensorsmentioning

confidence: 99%

“…The interaction between aptamers and AuNPs is required to develop a sensing platform. [64][65][66][67] However, this interaction cannot be stronger than the interaction within the aptamer-target complex as the sensor relies upon the aptamer leaving the AuNP surface to preferentially bind its target molecule in solution. As the interaction between the aptamer and the AuNP is non-covalent, the relative strength of this interaction relative to the interaction within the aptamer-target complex determines the success of the sensor.…”

Section: Current Challenges With Aptamer-based Gold Nanoparticle Assaysmentioning

confidence: 99%

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Gold Nanoparticles as a Platform for Small Molecule SELEX

Smith¹

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Both naturally occurring and synthetic small molecules play a significant role in a variety of applications. For example, small molecule food contaminants that occur infield or postharvest are of importance, both agriculturally and economically. Mycotoxins are toxic secondary metabolites produced by filamentous fungi that can potentially contaminate a variety of foodstuffs. Detection of these small molecules is required as mycotoxins pose multiple health-risks and proceed past processing and food safety.Current detection methods are expensive, time consuming and unavailable for on-site detection leaving an unmet need for alternative methods of detection.Aptamers are single stranded oligonucleotides that can bind to specific target molecules with high selectivity and affinity. Emerging as molecular recognition agents, aptamers can be used in a number of novel detection methods for small molecule quantification and analysis. Aptamers are selected through an in vitro process known as Systematic Evolution of Ligands by Exponential Enrichment (SELEX). Aptamers can be adsorbed onto the surface of citrate-capped AuNPs to serve as the molecular recognition element of a rapid colourimetric biosensor assay. Based on this interaction, AuNPs could potentially serve as a novel platform for small molecule SELEX. Although molecular recognition of small molecules is of great interest, selection of aptamers for small molecules has proven to be a challenge. Furthermore, not all of these reported small molecule aptamers can be easily incorporated in the AuNP bioassay. Selecting for aptamers in a manner that will mimic established AuNP biosensor conditions provides a number of advantages compared to traditional SELEX. As a first step towards establishing a AuNP SELEX platform, we evaluated the partitioning of mycotoxin iv aptamers that remain on the AuNP surface from aptamers-target complexes in solution.Having uncovered several challenges associated with AuNPs as a SELEX partitioning strategy, we next synthesized, optimized, and characterized core-shell gold coated magnetic nanoparticles (Fe3O4-AuNPs), which were phase-transferred aqueous solution.We demonstrated that Fe3O4-AuNPs could function as an improved AuNP SELEX platform and provide a novel method to study ssDNA aptamer-AuNP non-specific interactions. Finally, our studies on the adsorption and separation of ssDNA aptamers using Fe3O4-AuNPs highlight future opportunities for novel aptamer biomedical applications and other biosensor development.v

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Gold nanoparticle–based colorimetric aptasensor for rapid detection of six organophosphorous pesticides

Cited by 94 publications

References 48 publications

Fabrication of microfluidic device for Aflatoxin M1 detection in milk samples with specific aptamers

Fabrication of microfluidic device for Aflatoxin M1 detection in milk samples with specific aptamers

Red or Blue? Gold Nanoparticles in Colorimetric Sensing

Gold Nanoparticles as a Platform for Small Molecule SELEX

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