Serum Creatinine Detection by a Conducting-Polymer-Based Electrochemical Sensor To Identify Allograft Dysfunction

Abstract

Kidney transplant recipients who have abnormally high creatinine levels in their blood often have allograft dysfunction secondary to rejection. Creatinine has become the preferred marker for renal dysfunction and is readily available in hospital clinical settings. We developed a rapid and accurate polymer-based electrochemical point-of-care (POC) assay for creatinine detection from whole blood to identify allograft dysfunction. The creatinine concentrations of 19 blood samples from transplant recipients were measured directly from clinical serum samples by the conducting polymer based electrochemical (EC) sensor arrays. These measurements were compared to the traditional clinical laboratory assay. The time required for detection was less than 5 minutes from sample loading. Sensitivity of the detection was found to be 0.46 mg/dL of creatinine with only 40 μL sample in the creatinine concentration range of 0 mg/dL to 11.33 mg/dL. Signal levels that were detected electrochemically correlated closely with the creatinine blood concentration detected by the UCLA Ronald Reagan Medical Center traditional clinical laboratory assay (correlation coefficient 0.94). This work is encouraging for the development of a rapid and accurate POCT device for measuring creatinine levels in whole blood.

Colorimetric Detection of Creatinine Based on Plasmonic Nanoparticles via Synergistic Coordination Chemistry

“…Although the introduction of enzymes has improved specificity, it also rendered the method costly and nonportable, which limited the utility of this technique . Numerous alternative methods have also been developed, such as HPLC, isopotic dilution mass spectrometry (IDMS), electrochemical sensors, and capillary electrophoresis, which can qualitatively or/and quantitatively determine creatinine in different matrixes. However, these instrument‐based analytic approaches are rather complex and costly; and therefore unsuitable for the bulk analysis of clinical specimens.…”

Organic Electronics for Point-of-Care Metabolite Monitoring

“…(Figure 3a). [61] Liao and coworkers recently developed a flexible OECT platform based on PEDOT:PSS to selectively detect urea and glucose in saliva samples. [62] To eliminate electrochemical interference in saliva, thus enhancing sensitivity and selectivity, the gate electrodes were modified with oppositely charged bilayer polymeric films for both anionic and cationic charge exclusion of interferents.…”

Organic semiconductors for biological sensing

“…65,66 The benefit was to improve the performance of the sensor compared to the direct immobilization of the enzyme on the electrode surface, kindling the functionalization of polypyrrole with other biomolecules such as antibodies. 67,68 As early as 1992, an OECT containing polypyrrole was developed for use as a penicillin sensor. By coating a polypyrrole-based OECT with a cross-linked penicillinase membrane, penicillin-G in contact with the device was converted to penicilloic acid via enzyme-catalysed hydrolysis.…”