Aerosol Jet Printed 3D Electrochemical Sensors for Protein Detection

Abstract

The use of electrochemical sensors for the analysis of biological samples is nowadays widespread and highly demanded from diagnostic and pharmaceutical research, but the reliability and repeatability still remain debated issues. In the expanding field of printed electronics, Aerosol Jet Printing (AJP) appears promising to bring an improvement in resolution, miniaturization, and flexibility. In this paper, the use of AJP is proposed to design and fabricate customized electrochemical sensors in term of geometry, materials and 3D liquid sample confinement, reducing variability in the functionalization process. After an analysis of geometrical, electrical and surface features, the optimal layout has been selected. An electrochemical test has been then performed quantifying Interleukin-8, selected as reference protein, by means of Anodic Stripping Voltammetry. AJP sensors have been compared with standard screen-printed electrodes in terms of current density and relative standard deviation. Results from AJP sensors with Ag-based Anodic Stripping Voltammetry confirmed nanostructures capability to reduce the limit of detection (from 2.1 to 0.3 ng/mL). Furthermore, AJP appeared to bring an improvement in term of relative standard deviation from 50 to 10%, if compared to screen-printed sensors. This is promising to improve reliability and repeatability of measurement techniques integrable in several biotechnological applications.

Printed Smart Devices on Cellulose-Based Materials by means of Aerosol-Jet Printing and Photonic Curing

“…AJP is a full-additive, contactless printing manufacturing process composed of four key steps: Atomization of a liquid suspension by pneumatic or ultrasonic atomization thanks to a carrier gas (nitrogen or compressed dry air); generation of a mist of droplets (around 1-5 µm in diameter) passing through a virtual impactor to remove carrier gas and select droplets dimensions; focus of the stream by a sheath gas; deposition of the atomized ink on the substrate. This 3D printing technique was involved in the development of many applications, like high-efficiency solar and fuel cells, fully printed thin-film transistors, embedded resistors, antennas, MEMS, flexible displays and circuitry [33], photodetectors [34], wearable applications [35], thermistors [36], microelectrodes arrays for biosensing applications [37], lab-on-chip devices [38], protein [39] and glucose sensing [40].…”

Printed Electronics as Prepared by Inkjet Printing

“…While IJP generally produces line widths as small as 20 µm [5,6] on hydrophobic surfaces, AJP can produce even thinner lines down to 10 µm [7]. Moreover, AJP can print higher viscosity inks of up to 1000 cP as compared to IJP, which can only print viscous inks between 5-20 cP [8], enabling a wider range of functional materials to be used in AJP. The advantages of AJP make the technology particularly suitable for printed electronics applications [9,10] yet it is much less established than IJP and there are significantly less research findings covering AJP, mainly because the technology requires a much higher start-up cost.…”

Impedance-Based Monitoring of Mesenchymal Stromal Cell Three-Dimensional Proliferation Using Aerosol Jet Printed Sensors: A Tissue Engineering Application

“…Compared to those techniques, aerosol jet printing (AJP) allows an improvement both in terms of micrometer-resolution than in terms of the range of usable inks and substrates. Therefore, among the most recent technology used from this perspective, aerosol jet printing (AJP) indeed represents one of the most promising [30][31][32][33].…”