Rapid Conductometric Sensing of Chronic Kidney Disease Biomarkers: Specific and Precise Detection of Creatinine and Cystatin C in Artificial Saliva

Abstract

Chronic kidney disease (CKD) has asymptomatic early stages, whereby early detection is crucial to prevent its complications and progression. Creatinine and cystatin C (cysC) assays are known for assessing kidney function but there are limited point‐of‐care diagnostics which are rapid, precise, and easy to use. Here, high resistivity silicon conductometric sensors for detection of creatinine and cysC with a 10 min sample incubation is introduced. The sensors provide resistance‐based signals that can be quantified and measured wirelessly. The sensors successfully detect creatinine and cysC in both phosphate buffer saline (PBS) and artificial saliva in the nanomolar range, being able to distinguish their critical concentrations at 8.8 and 20 nm, respectively, for diagnosis of early stage of CKD. The detection limit for both creatinine and cysC is determined as 0.01 nm which is more than 500× and 1000× times lower than critical concentrations for the two biomarkers, respectively. Finally, these sensors are incorporated into a battery‐free, miniaturized electronic device for wireless biomarker detection as a proof‐of‐concept demonstration of a point‐of‐care tool for assessing kidney functionality.

Artificial optoelectronic synapses based on flexible and transparent oxide transistors

“…These challenges are addressed by identifying the combination of compatible fabrication techniques and appropriate materials that provide stretchable, bendable, biocompatible, and transparent properties, all while minimizing production costs and complexity at a large scale. Oxide semiconductors are of significant interest in flexible electronics because they can be deposited on flexible substrates at low temperatures and in nanometer-scale thicknesses, which are compatible with the thermal limitations of common flexible substrates Transistor devices offer substantially higher electrical performance than conventional flexible amorphous hydrogenated silicon transistors and can be produced at lower costs, making them promising new building blocks for flexible electronics [14].…”