Fabrication of folate functionalized polyoxometalate nanoparticle to simultaneously detect H2O2 and sarcosine in colorimetry

• Published in: Sensors and actuators. B, Chemical Vol. 304; p. 127429
• Main Authors: Mbage, Bawa, Li, Yiming, Si, Haipei, Zhang, Xueyan, Li, Yue, Wang, Xiaohong, Salah, Abdulwahab, Zhang, Kaizhi
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01-02-2020; Elsevier Science Ltd
• Subjects: Biomarkers; Colorimetric assay; Colorimetry; Folate acid functionalization; Glycine; H2O2; Hydrogen peroxide; Nanoparticles; Oxidation; Peroxidase; Polyoxometalate; Prostate; Sarcosine; Selectivity; Polyoxometalate; Colorimetric assay; H2O2; Folate acid functionalization; Sarcosine
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2019.127429

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•FA-PMo4V8 is used in colorimetric assay of H2O2 with detection limit as 0.012 μM.•FA-PMo4V8 catalyzes sarcosine in O2 to generate H2O2 without sarcosine oxidase.•FA-PMo4V8 showed high selectivity and detection limit of 0.311 μM for sarcosine.•Sarcosine in urine is detected with recoveries range 97.8–104.3 % with CV < 7 %.•Sarcosine is detected in prostate cancer urine by FA-PMo4V8.
The colorimetric detection of sarcosine, a possible biomarker of prostate cancer (PCa), is long-standing research interest and challenge. Folate functionalized polyoxometalate (FA-PMo4V8) was designed and found to detect H2O2 and sarcosine without using peroxidase and sarcosine oxidase (SOD) in 3,3,5,5-tetramethylbezidine (TMB) colorimetric reaction. At optimal condition, FA-PMo4V8 exhibited excellent peroxidase-like activity and catalyzed the oxidation of TMB during detection of H2O2 concentrations in the linear range of 0.007 to 4 μM at limit of detection of 0.012 μM. Also, FA-PMo4V8 was found to mimic SOD by reacting with sarcosine in the presence of oxygen to generate H2O2, glycine and formaldehyde. Sarcosine concentrations were indirectly detected by FA-PMo4V8 with the linear range of 0.2–500 μM at limit of detection of 0.311 μM. FA-PMo4V8 was easily fabricated and exhibited good selectivity, reproducible and sensitivity for detecting H2O2 and sarcosine in broader pH range. FA-PMo4V8 further discriminated PCa patients and healthy persons based on urinary sarcosine concentrations. This study demonstrated that FA-PMo4V8 is simply designed and accurate in colorimetric detection of urinary sarcosine, which could be useful for clinical applications.