“Turn-off” sensing probe based on fluorescent gold nanoclusters for the sensitive detection of hemin

Fereja, Shemsu Ligani; Fang, Zhongying; Li, Ping; Guo, Jinhan; Fereja, Tadesse Haile; Chen, Wei

doi:10.1007/s00216-020-03126-1

Cited by 13 publications

(9 citation statements)

References 55 publications

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“…The free hemin can conjugate with the Au NCs due to its special affinities to the surface proteins, as previously reported [25]. The known photoinduced electron transfer (PET) between hemin and Au NCs contributes to the remarkable decrease of fluorescence [26,27]. Consequently, the assay of S1 nuclease was achieved by examining the fluorescence intensity of Au NCs.…”

Section: Fluorescence Properties Of Au Ag Cu and Pt Ncsmentioning

confidence: 82%

General gel-sol method to synthesize various highly fluorescent nanoclusters and assay of nuclease with the near infrared-emitting gold nanoclusters

Xia

Luo

2023

Preprint

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A general egg white gel-sol strategy for fabrication of highly fluorescent Au, Ag, Cu and Pt nanoclusters (NCs) and the first example of using Au NCs for assay of nuclease activity and inhibition were described. The Au NCs enabled bright red fluorescence, and the other Ag, Cu and Pt NCs have highly blue emission. The red-emitting Au NCs were further applied in assay of S1 nuclease activity and inhibition. Free hemin efficiently quenches the emission of Au NCs by photoinduced electron transfer due to formation of Au NCs-hemin conjugates. However, G-quadruplex/hemin exerts negligible effect on its fluorescence due to no Au NCs-hemin conjugate formed. There are stronger electrostatic repulsion effects between both negatively charged G-quadruplex and Au NCs. Therefore, a novel G-quadruplex/hemin-based Au NCs fluorescent sensor for S1 nuclease was designed. A known G-rich oligonucleotide (ODN) serves as not only substrate for S1 nuclease but also for the construction of G-quadruplex/hemin. The G-rich ODN is hydrolyzed into fragments by S1 nuclease resulting in no G-quadruplex/hemin formation. Therefore, the free hemin quenches Au NCs fluorescence remarkably and the assay of S1 nuclease activity and inhibition has accomplished. Both the fluorescent NCs syntheses and the detection of S1 nuclease are facile and efficient.

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Section: Fluorescence Properties Of Au Ag Cu and Pt Ncsmentioning

confidence: 82%

General gel-sol method to synthesize various highly fluorescent nanoclusters and assay of nuclease with the near infrared-emitting gold nanoclusters

Xia

Luo

2023

Preprint

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“…The developed hemin-SDS- l -His system with TMB as a reducing substrate could be utilized directly or with some modifications if required for various applications. One example is the detection of hemin or hydrogen peroxide as an alternative method to the ones reported in the literature. − Our system appears to be advantageous in terms of simplicity of the preparation procedure and cost-efficiency. As reported in this work, hemin concentrations as low as 2 nM can be detected, although we did not investigate the limit of detection.…”

Section: Discussionmentioning

confidence: 99%

Optimization and Enhancement of the Peroxidase-like Activity of Hemin in Aqueous Solutions of Sodium Dodecylsulfate

Cvjetan,

Schuler,

Ishikawa

et al. 2023

ACS Omega

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Iron porphyrins play several important roles in present-day living systems and probably already existed in very early life forms. Hemin (= ferric protoporphyrin IX = ferric heme b), for example, is the prosthetic group at the active site of heme peroxidases, catalyzing the oxidation of a number of different types of reducing substrates after hemin is first oxidized by hydrogen peroxide as the oxidizing substrate of the enzyme. The active site of heme peroxidases consists of a hydrophobic pocket in which hemin is embedded noncovalently and kept in place through coordination of the iron atom to a proximal histidine side chain of the protein. It is this partially hydrophobic local environment of the enzyme which determines the efficiency with which the sequential reactions of the oxidizing and reducing substrates proceed at the active site. Free hemin, which has been separated from the protein moiety of heme peroxidases, is known to aggregate in an aqueous solution and exhibits low catalytic activity. Based on previous reports on the use of surfactant micelles to solubilize free hemin in a nonaggregated state, the peroxidase-like activity of hemin in the presence of sodium dodecyl sulfate (SDS) at concentrations below and above the critical concentration for SDS micelle formation (critical micellization concentration (cmc)) was systematically investigated. In most experiments, 3,3′,5,5′-tetramethylbenzidine (TMB) was applied as a reducing substrate at pH = 7.2. The presence of SDS clearly had a positive effect on the reaction in terms of initial reaction rate and reaction yield, even at concentrations below the cmc. The highest activity correlated with the cmc value, as demonstrated for reactions at three different HEPES concentrations. The 4-(2-hydroxyethyl)-1-piperazineethanesulfonate salt (HEPES) served as a pH buffer substance and also had an accelerating effect on the reaction. At the cmc, the addition of l-histidine (l-His) resulted in a further concentration-dependent increase in the peroxidase-like activity of hemin until a maximal effect was reached at an optimal l-His concentration, probably corresponding to an ideal mono-l-His ligation to hemin. Some of the results obtained can be understood on the basis of molecular dynamics simulations, which indicated the existence of intermolecular interactions between hemin and HEPES and between hemin and SDS. Preliminary experiments with SDS/dodecanol vesicles at pH = 7.2 showed that in the presence of the vesicles, hemin exhibited similar peroxidase-like activity as in the case of SDS micelles. This supports the hypothesis that micelle- or vesicle-associated ferric or ferrous iron porphyrins may have played a role as primitive catalysts in membranous prebiotic compartment systems before cellular life emerged.

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“…This short response time demonstrates that the sensing procedure follows the IFE process. [65,66] In other words, the interaction of hemoglobin molecules with the pepsin-CuNCs is not the decisive factor in quenching their luminescence. Additionally, the luminescence quenching of the pepsin-CuNCs induced by hemoglobin is independent of changes in the pH range of 4.0-7.0 (Figure 5d).…”

Section: Sensing Of Hemoglobinmentioning

confidence: 99%

Blue‐green emission of pepsin‐stabilized copper nanoclusters ultrafast detection of hemoglobin in human urine

Tseng

Wang

Aiyu

et al. 2022

J Chinese Chemical Soc

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This work proposed a straightforward synthesis of copper nanoclusters (CuNCs) with an emission wavelength of 496 nm and a quantum yield of 2.2% by directly using pepsin as a template with low toxicity NaBH4 and ascorbic acid as reducing agents. The chemical composition and optical properties of the pepsin-stabilized CuNCs (pepsin-CuNCs) were well-characterized by spectroscopy-related techniques. The pepsin-CuNCs retained the fluorescence intensity at neutral pH, at 37 C, and in high salinity, proving their suitability in biological systems. Although the pepsin-CuNCs remained only half of the initial fluorescence intensity after 24 days due to air oxidation, their storage stability was comparable to that of CuNCs reported in the literature. Given

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“Turn-off” sensing probe based on fluorescent gold nanoclusters for the sensitive detection of hemin

Cited by 13 publications

References 55 publications

General gel-sol method to synthesize various highly fluorescent nanoclusters and assay of nuclease with the near infrared-emitting gold nanoclusters

General gel-sol method to synthesize various highly fluorescent nanoclusters and assay of nuclease with the near infrared-emitting gold nanoclusters

Optimization and Enhancement of the Peroxidase-like Activity of Hemin in Aqueous Solutions of Sodium Dodecylsulfate

Blue‐green emission of pepsin‐stabilized copper nanoclusters ultrafast detection of hemoglobin in human urine

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