Browsing by Author "Inglis, DW"

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    IFN-γ-induced signal-on fluorescence aptasensors: from hybridization chain reaction amplification to 3D optical fiber sensing interface towards a deployable device for cytokine sensing
    (Royal Society of Chemistry, 2019-04-29) Zhang, FY; Deng, F; Liu, GJ; Middleton, RJ; Inglis, DW; Anwer, A; Wang, S; Liu, GZ
    Interferon-gamma (IFN-γ), a proinflammatory cytokine, has been used as an early indicator of multiple infectious diseases or tumors. In order to explore the detection capability of a commonly used anti-IFN-γ aptamer, a simple target induced strand-displacement aptasensing strategy was tested by introducing three different complementary strands and two different signal/quencher pairs. The Texas red/BHQ2-based sensor showed the best affinity constant (Kd) of 21.87 ng mL−1. It was found that the strand-displacement aptasensing strategy was impacted by the complementary position and length of the complementary strands. Additionally, the hybridization chain reaction (HCR) amplification strategy was introduced, yielding a 12-fold improved sensitivity of 0.45 ng mL−1. In order to further explore the sensing platform for spatially localized cytokine detection, the Texas red/BHQ2-based strand-displacement aptasensor was successfully fabricated on the 3D optical fiber surface to achieve a deployable sensing device for monitoring IFN-γ based on the fluorescence spots counting strategy. Finally, the three developed aptasensing strategies (strand-displacement strategy, HCR amplification strategy, 3D optical fiber aptasensor) were applied for detection of IFN-γ secreted by PBMCs with comparable results to those of ELISA. The deployable 3D optical fiber aptasensor with the superior sensitivity is potential to be used for detection of spatially localized IFN-γ in vivo. © 2019 The Royal Society of Chemistry
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    Turn-on fluorescence aptasensor on magnetic nanobeads for aflatoxin M1 detection based on an exonuclease III-assisted signal amplification strategy
    (Multidisciplinary Digital Publishing Institute (MDPI), 2019-01-16) Zhang, FY; Liu, LY; Ni, SN; Deng, JK; Liu, GJ; Middleton, RJ; Inglis, DW; Wang, S; Liu, GZ
    In order to satisfy the need for sensitive detection of Aflatoxin M1 (AFM1), we constructed a simple and signal-on fluorescence aptasensor based on an autocatalytic Exonuclease III (Exo III)-assisted signal amplification strategy. In this sensor, the DNA hybridization on magnetic nanobeads could be triggered by the target AFM1, resulting in the release of a single-stranded DNA to induce an Exo III-assisted signal amplification, in which numerous G-quadruplex structures would be produced and then associated with the fluorescent dye to generate significantly amplified fluorescence signals resulting in the increased sensitivity. Under the optimized conditions, this aptasensor was able to detect AFM1 with a practical detection limit of 9.73 ng kg−1 in milk samples. Furthermore, the prepared sensor was successfully used for detection of AFM1 in the commercially available milk samples with the recovery percentages ranging from 80.13% to 108.67%. Also, the sensor performance was evaluated by the commercial immunoassay kit with satisfactory results. © 2019 the Authors