Protein-Templated Copper Nanoclusters: Versatile Platform for Label-Free Detection of Albumin

The outstanding properties of metal nanoclusters, stabilized with different scaffolds, i.e., proteins, nucleic acids, polymers and dendrimers, enable their application in a wide range of fields. The recent advances in the fabrication and synthesis of nanoclusters have revolutionized the design of biosensors, leading to significant improvements in the selective and sensitive determination of several targets. In particular, in recent years, copper nanoclusters (CuNCs) have attracted more attention mainly for their unique fluorescent properties, as well as their large Stokes shifts, low toxicity, and high biocompatibility. The high-photoluminescent features of CuNCs facilitate highly sensitive target detection even in complex biological matrices. For these reasons, in this work, we exploited the specific template-targeted CuNCs’ growth for the sensitive and accurate determination of human serum albumin (HSA) in urine and human serum. HSA is the most abundant protein in plasma, acting as a carrier for many key biological molecules such as hormones, fatty acids and steroids, and it contributes to the maintenance of the oncotic blood pressure. The concentration of HSA in body fluids greatly influences the state of health of the patients. Taking into account these considerations, the quantitative detection of human serum albumin plays a key role in the early diagnosis of serious pathological conditions such as albuminuria and albuminemia. Here, we present a CuNCs-based assay in which copper nanoclusters were used as fluorescent signal indicators to detect serum albumin in a complex biological matrix.

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Protein-templated copper nanoclusters for fluorimetric determination of human serum albumin

Microchimica Acta ◽

10.1007/s00604-021-04764-7 ◽

2021 ◽

Vol 188 (4) ◽

Author(s):

Mariagrazia Lettieri ◽

Pasquale Palladino ◽

Simona Scarano ◽

Maria Minunni

Keyword(s):

Human Serum Albumin ◽

Serum Albumin ◽

Human Serum ◽

Fluorescent Detection ◽

Fluorimetric Determination ◽

Copper Nanoclusters ◽

Optical Reporters ◽

The Stability ◽

Serum And Urine

AbstractCopper nanoclusters (CuNCs) are attractive for their unique optical properties, providing sensitive fluorescent detection of several kinds of targets even in complex matrices. Their ability in growing on suitable protein and nucleic acid templates make CuNCs efficient optical reporters to be exploited in bioanalysis. In this work, we report the specific and sensitive determination of human serum albumin (HSA) in human serum (HS) and urine via CuNCs fluorescence. HSA is the most abundant protein in plasma, and plays a key role in the early diagnosis of serious pathological conditions such as albuminuria and albuminemia. Recently, HSA has become clinically central also as a biomarker to assess severity, progression, and prognosis of various cancers. We report the controlled and reproducible growth of CuNCs directly on the target analyte, HSA, which results in a fine dose-dependent fluorescent emission at 405 nm. The protocol is optimized in water, and then applied to serum and urine specimens, without matrix pretreatment. The method linearly responds within the whole concentration of clinical interest, with a sensitivity of 1.8 ± 0.1 × 10−3 g L−1 and 0.62 ± 0.03 × 10−3 g L−1 in serum and urine, respectively, and excellent reproducibility (CVav% ca. 3% for both). The assay is designed to have a single protocol working for both matrices, with recovery of 95% (HS) and 96% (urine). The stability of the fluorescence after CuNCs formation was tested over 3 days, displaying good results (yet higher in urine than in serum). Graphical abstract

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Chemometrics-assisted multi-instrumental techniques for investigation of interactions of dapagliflozin with normal and glycated human serum albumin: Application to exploiting second-order advantage for determination of glycated human serum albumin as a biomarker for controlling diabetes

Microchemical Journal ◽

10.1016/j.microc.2021.106313 ◽

2021 ◽

Vol 167 ◽

pp. 106313

Author(s):

Asma Mohamady ◽

Mohsen Shahlaei ◽

Vali Akbari ◽

Hector C. Goicoechea ◽

Ali R. Jalalvand

Keyword(s):

Human Serum Albumin ◽

Serum Albumin ◽

Human Serum ◽

Second Order

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Simultaneous Determination of Human Serum Albumin and Low-Molecular-Weight Thiols after Derivatization with Monobromobimane

Molecules ◽

10.3390/molecules26113321 ◽

2021 ◽

Vol 26 (11) ◽

pp. 3321

Author(s):

Katarzyna Kurpet ◽

Rafał Głowacki ◽

Grażyna Chwatko

Keyword(s):

Molecular Weight ◽

Human Serum Albumin ◽

Serum Albumin ◽

Human Serum ◽

Simultaneous Determination ◽

Reversed Phase ◽

Fluorescence Labeling ◽

Detector Response ◽

Low Molecular Weight

Biothiols are extremely powerful antioxidants that protect cells against the effects of oxidative stress. They are also considered relevant disease biomarkers, specifically risk factors for cardiovascular disease. In this paper, a new procedure for the simultaneous determination of human serum albumin and low-molecular-weight thiols in plasma is described. The method is based on the pre-column derivatization of analytes with a thiol-specific fluorescence labeling reagent, monobromobimane, followed by separation and quantification through reversed-phase high-performance liquid chromatography with fluorescence detection (excitation, 378 nm; emission, 492 nm). Prior to the derivatization step, the oxidized thiols are converted to their reduced forms by reductive cleavage with sodium borohydride. Linearity in the detector response for total thiols was observed in the following ranges: 1.76–30.0 mg mL−1 for human serum albumin, 0.29–5.0 nmol mL−1 for α-lipoic acid, 1.16–35 nmol mL−1 for glutathione, 9.83–450.0 nmol mL−1 for cysteine, 0.55–40.0 nmol mL−1 for homocysteine, 0.34–50.0 nmol mL−1 for N-acetyl-L-cysteine, and 1.45–45.0 nmol mL−1 for cysteinylglycine. Recovery values of 85.16–119.48% were recorded for all the analytes. The developed method is sensitive, repeatable, and linear within the expected ranges of total thiols. The devised procedure can be applied to plasma samples to monitor biochemical processes in various pathophysiological states.

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