Current Technologies of Electrochemical Immunosensors: Perspective on Signal Amplification

Cho, Il Hoon; Lee, Jongsung; Kim, Jiyeon; Kang, Min Soo; Paik, Jean Kyung; Ku, Seockmo; Cho, Hyun Mo; Irudayaraj, Joseph; Kim, Dong Hyung

doi:10.3390/s18010207

Cited by 193 publications

(134 citation statements)

References 93 publications

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“…[7] On the other hand, colorimetric sensor produce visible color changes upon the presence of the virus genes. [7] On the other hand, colorimetric sensor produce visible color changes upon the presence of the virus genes.…”

mentioning

confidence: 99%

Upconversion Luminescence Sandwich Assay For Detection of Influenza H7 Subtype

Tsang

Wong

Tsoi

et al. 2019

Adv Healthcare Materials

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Those sensors increase the limits of detection (LOD) by using signal amplifiers but the hybridization times are usually long. [7] On the other hand, colorimetric sensor produce visible color changes upon the presence of the virus genes. The simplicity in design and readout of these sensors had attracted substantial attention. Gold nanoparticles (AuNPs) are one of the promising candidates for such detection strategy because of their high extinction coefficient and aggregation-dependent color change. [8,9] Despite the advantages, AuNPs are surface-sensitive and may induce undesired aggregations due to high ionic strength and concentration of ions, resulting in false-positive signals.Apart from those approaches, optical detection has drawn substantial attention because of their simplicity, sensitiveness, and multiplexity. [10,11] It is the fact that organic dyes are widely used in conventional qPCR assays via downconversion processes. [4,12,13] However, the dyes demonstrate undesirable emissive properties such as poor photostability, broad emission band, and small Stokes shift. [14] Therefore, they were usually employed as quenchers in nanoparticle-based detection systems. [15][16][17] High energy excited quantum dots (QDs) are another representative fluorophores in downconverting assays. [18][19][20] The excitation may induce background fluorescence and broad emission peaks, contributing to severe cross-talking problem. To address these limitations, nearinfrared (NIR) triggered upconversion luminescence (UCL) in lanthanide-doped upconversion nanoparticles (UCNPs) is very promising in biodetection. They not only display large anti-Stokes shift [21,22] but also pose minimal damage to the gene oligos. In addition, the long-lived UCL signal is easily distinguished from the short-lived background signal. As a result, UCNPs were used to detect different oligos and analytes. [23][24][25][26][27][28] The assays involved highly distance-dependent luminescence resonance energy transfer (LRET) between energy donor and acceptor, in which the luminescent intensity changes with the separation between the energy pair. [29] In this work, green emitting UCNPs and AuNPs are selected as the LRET pair owing to their well-matched emission and extinction spectrum, while AuNPs exhibit excellent extinction coefficient and photostability. The size of the nanoparticles played important roles in hybridization [30] because AuNPs demonstrate sizedependent absorption property and it can alter the stability of the hybridized DNA duplex. In addition, the size ratios of the UCNPs and AuNPs affect the formation of UCNPs-AuNPs hybrid structures. Taking advantages of 808 nm excitation of With large anti-Stokes shifts and background-free signals, upconversion luminescent (UCL) screening assays have been a promising method to reduce the transmission of influenza epidemic, which can critically alleviate the disease burden and extra annual deaths. In this work, a luminescent resonance energy transfer sandwich assay is developed, which utilizes core-shell...

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mentioning

confidence: 99%

Upconversion Luminescence Sandwich Assay For Detection of Influenza H7 Subtype

Tsang

Wong

Tsoi

et al. 2019

Adv Healthcare Materials

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“…Α considerable amount of scientific effort has been put towards increasing the sensitivity of an immunosensor through the optimization of either the way the recognition elements is immobilized onto the transducer surface or the morphology of the surface itself or both. As far as the latter is concerned, carbon nanotubes, noble metal nanoparticles, polymers, quantum dots, and graphene are some of the numerous nanomaterials that have been applied in the design of an immunosensor to amplify signal detection, enrich and concentrate trace analytes, and immobilize the recognition elements with enhanced stability [9][10][11][12].…”

Section: Introductionmentioning

confidence: 99%

Comparative Assessment of Affinity-Based Techniques for Oriented Antibody Immobilization towards Immunosensor Performance Optimization

et al. 2019

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Immunosensor sensitivity and stability depend on a number of parameters such as the orientation, the surface density, and the antigen-binding efficiency of antibodies following their immobilization onto functionalized surfaces. A number of techniques have been developed to improve the performance of an immunosensor that targets one or both of the parameters mentioned above. Herein, two widely employed techniques are compared for the first time, which do not require any complex engineering of neither the antibodies nor the surfaces onto which the former get immobilized. To optimize the different surface functionalization protocols and compare their efficiency, a model antibody-antigen system was employed that resembles the complex matrices immunosensors are frequently faced with in real conditions. The obtained results reveal that protein A/G is much more efficient in increasing antibody loading onto the surfaces in comparison to boronate ester chemistry. Despite the fact, therefore, that both contribute towards the orientation-specific immobilization of antibodies and hence enhance their antigen-binding efficiency, it is the increased antibody surface density attained with the use of protein A/G that plays a critical role in achieving maximal antigen recognition.

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“…or nucleic acids. The immunoassays have been reported as versatile and powerful tool in several analytical and biotechnology applications [79,80]. Their use leads to improve the analytical performances of the biosensors (refer to Figure 1).…”

Section: Immunosensorsmentioning

confidence: 99%

Nano-Biosensing Platforms for Detection of Cow’s Milk Allergens: An Overview

Nehra

Lettieri

Dilbaghi

et al. 2019

Sensors

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Among prevalent food allergies, cow milk allergy (CMA) is most common and may persist throughout the life. The allergic individuals are exposed to a constant threat due to milk proteins’ presence in uncounted food products like yogurt, cheese, and bakery items. The problem can be more severe due to cross-reactivity of the milk allergens in the food products due to homologous milk proteins of diverse species. This problem can be overcome by proper and reliable food labeling in order to ensure the life quality of allergic persons. Therefore, highly sensitive and accurate analytical techniques should be developed to detect the food allergens. Here, significant research advances in biosensors (specifically immunosensors and aptasensors) are reviewed for detection of the milk allergens. Different allergic proteins of cow milk are described here along with the analytical standard methods for their detection. Additionally, the commercial status of biosensors is also discussed in comparison to conventional techniques like enzyme-linked immunosorbent assay (ELISA). The development of novel biosensing mechanisms/kits for milk allergens detection is imperative from the perspective of enforcement of labeling regulations and directives keeping in view the sensitive individuals.

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Current Technologies of Electrochemical Immunosensors: Perspective on Signal Amplification

Cited by 193 publications

References 93 publications

Upconversion Luminescence Sandwich Assay For Detection of Influenza H7 Subtype

Upconversion Luminescence Sandwich Assay For Detection of Influenza H7 Subtype

Comparative Assessment of Affinity-Based Techniques for Oriented Antibody Immobilization towards Immunosensor Performance Optimization

Nano-Biosensing Platforms for Detection of Cow’s Milk Allergens: An Overview

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