Pysanka-Inspired Electrode Modification with Aptamer Encapsulation in ZIF-8 for Urine Creatinine Electrochemical Biosensing

Abstract

Drawing inspiration from the several thousand beautiful Pysanky egg art of Ukraine, we have developed a novel material, Aptamer–Gold Nanoparticles (AuNPs)@ZIF-8, that can be used for building sensitive and highly stable POC biosensors for longitudinal health mapping. Here, we demonstrate a sensitive and specific novel electrochemical biosensor, made of a novel synthesized in situ encapsulated aptamer-AuNPs@ZIF-8 composite, for monitoring levels of creatinine (0.1–1000 μg/mL). In this work, we have reported the synthetic protocol for the first-of-a-kind in situ encapsulation of aptamer and AuNPs together in a ZIF-8 matrix, and explored the characteristic properties of this novel material composite using standard analytical techniques and its application for biosensor application. The as-synthesized material, duly characterized using various physicochemical analytical methods, portrays the characteristics of the unique encapsulation strategy to develop the first-of-a-kind aptamer and AuNP encapsulation. Non-faradaic Electrochemical Impedance Spectroscopy (EIS) and Chronoamperometry were used to characterize the interfacial electrochemical properties. The biosensor performance was first validated using artificial urine in a controlled buffer medium. The stability and robustness were tested using a real human urine medium without filtration or sample treatment. Being versatile, this Ukrainian-art-inspired biosensor can potentially move the needle towards developing the next generation of sample-in-result-out robust POC diagnostics.

Effect of Applied AC Voltage on the Performance of Non-Faradaic Impedimetric Biosensors

“…18,19 To the best of authors' knowledge, the effect of applied AC voltage on the linearity of bare Au-IDEs during non-faradaic EIS measurements was not investigated in the past, nor was the effect of applied AC voltage on the performance of fully functionalized biosensors for the detection of biomarkers. [20][21][22][23] As previously mentioned, the commonly used AC voltage in non-faradaic EIS measurements is 10 mV with few researchers attempted biosensing with an applied AC voltage of 50 mV. In this regard, we report for the first time the effect of applied AC voltage on bare Au-IDEs electrodes using non-faradaic EIS mode.…”