Comparing two cortisol aptamers for label-free fluorescent and colorimetric biosensors

Niu, Chenqi; Ding, Yuzhe; Zhang, Chong; Liu, Juewen

doi:10.1039/d2sd00042c

Cited by 18 publications

(20 citation statements)

References 56 publications

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“…The original CSS.1 with a 6 bp stem generated the largest fluorescence difference with a K d of 1.1 μM. This K d value was very close to the K d measured by ITC (0.7 μM), 16 verifying that PMNT showed very little interference on aptamer binding.…”

Section: ■ Introductionsupporting

confidence: 76%

“…14,15 The conformational change of aptamers after target binding can either promote dye binding or displace dye molecules, resulting in a fluorescence intensity change. 16,17 However, these label-free biosensors show relatively low fluorescence change due to the noncanonical structures of aptamers. Strategies using terminal-labeled fluorophore and quencher pairs to form aptamer beacons were also employed.…”

Section: ■ Introductionmentioning

confidence: 99%

“…The cortisol aptamer (CSS.1) has a stable stem-loop secondary structure with a 6 bp stem and two small hairpins were predicted in the loop region (Figure 4A). 16 Thus, binding of cortisol may only induce some local conformational changes of the aptamer. We first optimized the aptamer concentration.…”

Section: ■ Introductionmentioning

confidence: 99%

“…This aptamer was insensitive to the concentration of NaCl, although the binding of CSS.1 and cortisol was promoted by Mg 2+ , which was consistent with a previous report. 16 The effect of Mg 2+ saturated at 10 mM. We then studied the effect of aptamer stem length.…”

Section: ■ Introductionmentioning

confidence: 99%

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General Label-Free Fluorescent Aptamer Binding Assay Using Cationic Conjugated Polymers

Qin

Lopez

et al. 2022

Anal. Chem.

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With more and more new aptamers being reported, a general, cost-effective yet reliable aptamer binding assay is still needed. Herein, we studied cationic conjugated polymer (CCP)-based binding assays taking advantage of the conformational change of aptamer after binding with a target, which is reflected by the fluorescence change of the CCP. Poly(3-(3′-N,N,N-triethylamino-1′-propyloxy)-4-methyl-2,5-thiophene hydrochloride) (PMNT) was used as a model CCP in this study, and the optimal buffer was close to physiological conditions with 100 mM NaCl and 10 mM MgCl2. We characterized four aptamers for K+, adenosine, cortisol, and caffeine. For cortisol and caffeine, the drop in the 580 nm peak intensity was used for quantification, whereas for K+ and adenosine, the fluorescence ratio at 580 over 530 nm was used. The longer stem of the stem-loop structured aptamer facilitated binding of the target and enlarged the detection signal. High specificity was achieved in differentiating targets with analogues. Compared with the SYBR Green I dye-based staining method, our method achieved equal or even higher sensitivity. Therefore, this assay is practicable as a general aptamer binding assay. The simple, label-free, quick response, and cost-effective features will make it a useful method to evaluate aptamer binding. At the same time, this system can also serve as label-free biosensors for target detection.

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Section: ■ Introductionsupporting

confidence: 76%

Section: ■ Introductionmentioning

confidence: 99%

Section: ■ Introductionmentioning

confidence: 99%

Section: ■ Introductionmentioning

confidence: 99%

See 2 more Smart Citations

General Label-Free Fluorescent Aptamer Binding Assay Using Cationic Conjugated Polymers

Qin

Lopez

et al. 2022

Anal. Chem.

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“…A cortisol aptamer (CSS.1) reported by the Stojanovic group was used ( Figure A), [ 51 ] and we previously reported that cortisol does not have strong interactions with AuNPs. [ 52 ] The optimal concentration of aptamer was determined to be 500 n m (Figure S8, Supporting Information), where the slope started to plateau and the solution color turned blue. In addition, a nonbinding mutant (CSS.1‐mt) was also used.…”

Section: Resultsmentioning

confidence: 99%

Reversible and Irreversible HAuCl₄ Binding to DNA for Seeded Gold Nanoparticle Growth and Opposite DNA and Aptamers Colorimetric Sensing Outcomes

Zandieh

Zheng

et al. 2022

Part & Part Syst Charact

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DNA‐directed seeded growth of gold nanoparticles has been used for the development of aptamer‐based biosensors with the assumption that target analytes can modulate the adsorption of aptamers to the gold seeds and thus affect the growth reaction. To understand the reaction, the effect of single‐ and double‐stranded DNA is first examined, and it is found that they have a similar promotion effect of anisotropic growth, suggesting that DNA cannot be detected using this method. By studying the interaction between HAuCl4 and DNA, both weak reversible binding and strong irreversible binding are identified, with the latter becoming dominating with a longer incubation time. Single‐ and double‐stranded DNA have similar weak binding to HAuCl4, and this weak binding is more important for the growth reaction. Then three aptamers are tested, where only cortisol appeared to modulate its aptamer adsorption and the growth reaction reflected aptamer binding. Hg2+ shows no advantage for its aptamer, and quinine induced aggregation of AuNPs cannot be detected by this reaction either. Therefore, each aptamer target needs to be individually studied to test if this method is applicable. It is also noted that DNA and aptamers have opposite outcomes for the target‐dependent growth reactions.

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Wearable and Implantable Cortisol‐Sensing Electronics for Stress Monitoring

Park

Jung

et al. 2023

Advanced Materials

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Cortisol is a steroid hormone that is released from the body in response to stress. Although a moderate level of cortisol secretion can help the body maintain homeostasis, excessive secretion can cause various diseases, such as depression and anxiety. Conventional methods for cortisol measurement undergo procedures that limit continuous monitoring, typically collecting samples of bodily fluids, followed by separate analysis in a laboratory setting that takes several hours. Thus, recent studies demonstrate wearable, miniaturized sensors integrated with electronic modules that enable wireless real‐time analysis. In this review, we primarily focus on wearable and implantable electronic devices that continuously measure cortisol concentration. We discuss diverse types of cortisol sensing techniques, such as antibody‐, DNA aptamer‐, and molecularly imprinted polymer‐based sensors, as well as wearable and implantable devices that aim to continuously monitor cortisol in a minimally invasive fashion. In addition to the cortisol monitors that directly measure stress levels, we also summarize other schemes that indirectly measure stress, such as electrophysiological signals and sweat. Finally, we review the challenges and future directions in stress monitoring and management electronics.This article is protected by copyright. All rights reserved

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Comparing two cortisol aptamers for label-free fluorescent and colorimetric biosensors

Abstract: Cortisol is a stress hormone and the abnormal secretion of cortisol is related to many chronical diseases and neurological disorders. To detect cortisol, two DNA aptamers have been reported so...

Cited by 18 publications

References 56 publications

General Label-Free Fluorescent Aptamer Binding Assay Using Cationic Conjugated Polymers

General Label-Free Fluorescent Aptamer Binding Assay Using Cationic Conjugated Polymers

Reversible and Irreversible HAuCl₄ Binding to DNA for Seeded Gold Nanoparticle Growth and Opposite DNA and Aptamers Colorimetric Sensing Outcomes

Wearable and Implantable Cortisol‐Sensing Electronics for Stress Monitoring

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Comparing two cortisol aptamers for label-free fluorescent and colorimetric biosensors

Abstract: Cortisol is a stress hormone and the abnormal secretion of cortisol is related to many chronical diseases and neurological disorders. To detect cortisol, two DNA aptamers have been reported so...

Cited by 18 publications

References 56 publications

General Label-Free Fluorescent Aptamer Binding Assay Using Cationic Conjugated Polymers

General Label-Free Fluorescent Aptamer Binding Assay Using Cationic Conjugated Polymers

Reversible and Irreversible HAuCl4 Binding to DNA for Seeded Gold Nanoparticle Growth and Opposite DNA and Aptamers Colorimetric Sensing Outcomes

Wearable and Implantable Cortisol‐Sensing Electronics for Stress Monitoring

Contact Info

Product

Resources

About

Reversible and Irreversible HAuCl₄ Binding to DNA for Seeded Gold Nanoparticle Growth and Opposite DNA and Aptamers Colorimetric Sensing Outcomes