Point-of-care-ready nanoscale ISFET arrays for sub-picomolar detection of cytokines in cell cultures

Abstract

Rapid and frequent screening of cytokines as immunomodulation agents is necessary for precise interventions in severe pathophysiological conditions. In addition to high-sensitivity detection of such analytes in complex biological fluids such as blood, saliva, and cell culture medium samples, it is also crucial to work out miniaturized bioanalytical platforms with potential for high-density integration enabling screening of multiple analytes. In this work, we show a compact, point-of-care-ready bioanalytical platform for screening of cytokines such as interleukin-4 (IL-4) and interleukin-2 (IL-2) based on one-dimensional ion-sensitive field-effect transistors arrays (nanoISFETs) of silicon fabricated at wafer-scale via nanoimprint lithography. The nanoISFETs biofunctionalized with receptor proteins alpha IL-4 and alpha IL-2 were deployed for screening cytokine secretion in mouse T helper cell differentiation culture media, respectively. Our nanoISFETs showed robust sensor signals for specific molecular binding and can be readily deployed for real-time screening of cytokines. Quantitative analyses of the nanoISFET-based bioanalytical platform was carried out for IL-4 concentrations ranging from 25 fg/mL (1.92 fM) to 2.5 μg/mL (192 nM), showing a limit of detection down to 3–5 fM, which was found to be in agreement with ELISA results in determining IL-4 concentrations directly in complex cell culture media.

Large-Area Interfaces for Single-Molecule Label-free Bioelectronic Detection

“…Figure 12A shows CNTs fabricated on silicon wafer. A zoomed-in view of a single transistor channel is [25][26][27][28][29]95,117,118 displayed. CNTs were patterned between source and drain, and the metal contacts were passivated by photoresist, thus preventing their direct contact with the electrolyte.…”

Point‐of‐care detection of cytokines in cytokine storm management and beyond: Significance and challenges

“…[ 135 ] For example, one‐dimensional ion‐sensitive FET arrays (nanoISFETs) on silicon nanowire were fabricated for continuous POC detection of cytokines (IL‐4 and IL‐2) secreted in mouse T helper cell differentiation culture media. [ 136 ] Such portable sensing platform was able to detect IL‐4 concentrations with a broad dynamic range between 25 fg/mL (1.92 fM) and 2.5 μg/mL (192 nM) with a detection limit down to 35 fM, indicating a highly adaptive platform for human cytokine POC test. In another study, Zhao and coworker developed a graphene‐based fully integrated portable FET sensing system for online detection of IL‐6 within 400 seconds in saliva with a detection limit down to 12 pM (Figure 2E).…”

A handheld intelligent single-molecule binary bioelectronic system for fast and reliable immunometric point-of-care testing

“…Bioelectronic sensors are, in principle, ideal for field-deployable diagnostic as they can be produced at a low cost and can provide an electronic response for direct digital data communication (14)(15)(16)(17)(18)(19)(20). State-of-the-art bioelectronic technologies operating at the lowest possible LOD of 1 entity in 0.1 ml have been based so far on organic (21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34) or graphene (16) bioelectronic field-effect transistors (FETs).…”