A homogeneous fluorescent sensor for human serum albumin

Abstract

Human serum albumin is the most abundant protein in the body and is an important biomarker used for disease-related diagnosis. Although the traditional enzyme-linked immunosorbent assay (ELISA) approach can precisely measure the concentration of human serum albumin, the multi-step procedure and time-consuming preparations of ELISA limit its diagnostic applications, preventing accurate point-of-care testing, for example. Herein, we report the recent development of an antibody-based albumin sensor that allows for a homogeneous measurement of albumin concentrations in saliva, urine and serum, in which this type of sensor is validated for the first time. The assay only requires simple mixing, and relies on time-resolved (TR) fluorescence resonance energy transfer (FRET) to produce robust, sensitive signals. The whole process, from sample preparation to final read-out, is expected to take less than one hour and requires only a standard plate-reader, thus making the sensor a convenient and cost-effective tool for albumin analysis.

Novel adsorptive materials by adenosine 5ʹ‐triphosphate imprinted‐polymer over the surface of polystyrene nanospheres for selective separation of adenosine 5ʹ‐triphosphate biomarker from urine

“…A similar observation also reported that the binding capacity of a cryogel towards template human serum albumin (HSA) present in non‐diluted serum is 390.2 mg/g whereas the binding capacity in binding studies is 25.9 mg/g , and also in our previous work reported, MIP towards HSA showed maximum adsorption capacity in urine (129.5 mg/g) whereas the binding capacity in binding studies is 86.7 mg/g . The UA , creatinine , and HSA in the human urine are found to be as ∼0.63–13.6 mM, ∼2.12–17.1 mM, and ∼0.2–0.39 µM, respectively. However, the adsorption capacity of human serum albumin (IF, 1.05) as well as creatinine (IF, 1.21) and uric acid (IF, 1.15), which are final metabolites in urine, is not very significant compared to ATP adsorption efficiency, suggesting that the interference of other metabolites to these ATP binding sites is nonspecific.…”

Efficient adsorptive extraction materials by surface protein‐imprinted polymer over silica gel for selective recognition/separation of human serum albumin from urine

“…Similar to HSA, UV visible spectra showed the absorption band at 280 nm for the urine sample. Also, the concentration of protein in urine is calculated to be 3.38 ± 0.0012 mg L −1 which is absent in the synthetic urine sample and is in the range of literature . The binding capacity of MIP toward HSA in real urine (125.3 mg g −1 ) is higher than in the synthetic urine (62.5 mg g −1 ) due to other peptides present in the real urine which indicated that the effect of amounts of the diffused protein template, that was associated with the perturbation of the complex interferences in the urine.…”

“…All other solvents and chemicals were obtained from RCI Labscan Ltd (Samutsakorn, Thailand), were of either analytical reagent grade or high‐performance liquid chromatography (HPLC) grade, and were used as received unless otherwise stated. Synthetic urine was prepared in deionized water using the following components: urea (1.2 × 10 −2 mol L −1 ), creatinine (1.3 × 10 −2 mol L −1 ), MgCl 2 (2.0 × 10 −3 mol L −1 ), CaCl 2 (2.0 × 10 −3 mol L −1 ), NaH 2 PO 4 .2H 2 O (8.0 × 10 −3 mol L −1 ), NH 4 Cl (8.0 × 10 −3 mol L −1 ), K 2 SO 4 (1.0 × 10 −2 mol L −1 ), and NaCl (1.6 × 10 −2 mol L −1 ). Synthetic urine and healthy human urine samples were diluted 10 times with phosphate‐buffered solution (PBS, pH 7.0) and added the known amount of HSA and used in further studies.…”

“…The variant levels of HSA in the blood and urine measure the sign of clearing blood fluid and reflux in urine that incorporated to an HSA homeostasis. The reference range for albumin concentrations in the blood is 35–50 g L −1 and the urine albumin is varied in the range of 2.2–25 mg L −1 . A diagnosis of HSA is used to study the human health and diseases, which is useful for drug development in the pharmaceutical industry and clinical analysis applications.…”

A ‘turn‐on’ fluorescent chemosensor for quantification of serum albumin in aqueous solution at neutral pH

“…Although these methods could complete the analysis accurately, they usually suffer from drawbacks such as insensitivity, narrow linear range and complicated detection procedures, etc. Therefore, the search for a sensitive, reliable, and convenient approach for detecting serum albumin has attracted increasing interests (9)(10)(11)(12)(13). Fluorescent chemosensors, which have been reported to be valid for the detection of serum albumin in the past few years, have attracted increasing interests due to their merits of high sensitivity, fast analysis, non-destructive emission signals and low cost (14)(15)(16)(17)(18)(19)(20).…”