3D-Printed integrated devices for bioelectroanalytical diagnostics and sensing

Additive Manufacturing (AM), commonly known as 3D printing, has emerged as a powerful technology in electrochemistry, offering rapid prototyping, design freedom, and the ability to produce integrated devices, providing a unique route to on-demand, low-cost (bio)analytical platforms. AM enables the integration of hybrid architectures within a single device, in which 3D printing provides the structure, fluidic system, mechanical frame, and functional components, manufactured using complementary technologies (e.g., paper-based sensors, stencil-printed electrodes, immunochemical elements), can be readily integrated as needed. In this way, compact, portable, reproducible systems can be produced in series, minimizing human involvement. From an analytical perspective, this approach enables the automation of analytical procedures, yielding fully integrated analysis systems on board 3D devices. In this presentation, two representative 3D-printed electrochemical platforms are presented. (i) A 3D-printed analytical device integrating functional paper components for the direct determination of amitraz in apicultural matrices. The platform combines a 3D-printed microfluidic architecture with interchangeable paper-based electrochemical sensors and a ‘hydrolysis-paper’ component that enables in situ conversion of amitraz into its electroactive metabolite, 2,4-dimethylaniline (2,4-DMA). The integration of functional paper substrates into the 3D-printed structure enables sample processing and sensing on a single device, achieving sensitive, reproducible, and low-cost detection of amitraz in honey and beeswax within a few minutes, without the need for sample pretreatment. (ii) An integrated 3D-printed electrochemical microfluidic device for immunocapture and electrochemical assessment of transferrin saturation (TSAT) in human serum. This device is entirely produced via AM and comprises a platform that incorporates a rotary-valve-controlled microfluidic network, an on-device immunoassay module, and an electrochemical cell fabricated by combining conductive filaments (CB-PLA) and non-conductive filaments (PLA). The system enables selective isolation of transferrin (Tf) and simultaneous electrochemical detection of Tf and Tf-bound iron directly from untreated human serum, providing clinically relevant information with significantly reduced analysis time compared with conventional methods. (iii) Eventually, if worthy of note, additional findings and future perspectives on 3D manufacturing of bioelectroanalytical devices will be presented. The proposed devices offer clear advantages in versatility, portability, and cost-effectiveness, positioning 3D printing as a pivotal technology for developing next-generation electrochemical systems for on-field and Point-of-Care testing. Summing up, this presentation demonstrates that AM offers possibilities beyond the fabrication of PLC-CB-based electrochemical sensors, enabling the seamless integration of heterogeneous functional components into all-in-one analytical devices that encompass complete analytical processes.