Multifunctional 4D-printed redox-responsive needle panel meter employing geometric changes for glucose and lactate concentration measurements

• The 4DP-NPM exhibited desirable attributes pertinent to on-site GLU & LAC sensing. • GLU & LAC detection was based on needle deflection without the need for electricity. • It can detect as low as 0.21 µM GLU & 0.11 µM LAC from samples of high-salt matrices. • It garnered operation simplicity, ease of needle replacement & marked storage stability. • Low cost of production would make it affordable and accessible in developing countries. Most biosensors routinely used for the detection of body metabolites commonly suffer from low patient compliance due to invasive sampling, high cost, and lack of portability for point-of-care (POC) diagnostic applications. Thus, we aimed to fabricate robust, user-friendly, affordable, and redox-responsive four-dimensional (4D)-printed needle panel meter (NPM) from 2,2ꞌ-(Ethylenedioxy)diethanethiol (EDDT) and Phrozen resin (PR) for glucose (GLU) and lactate (LAC) detection from blood, sweat and urine samples. Optimal needle bending was noticed upon the addition of target analytes into the NPM containing glucose oxidase (GOx, 5 U/mL, p H = 5.0, 20 min) or lactate oxidase (LOx, 0.01 U/mL, p H = 7.0, 45 min) and reversed back when reduced with NaBH 4 (1.25 wt%). To ensure its feasibility and equitable distribution in underprivileged sub-Saharan African countries (SSACs), three sets of concentration scale marks analogous to the temperature ranges of 20-26℃, 27-33℃, and 34-40℃ were adopted. The NPM precisely measured significantly low concentrations of GLU and LAC in high-salt matrix samples with considerably low limits of detection (LOD): 0.21 and 0.11 µM, respectively. In conclusion, the reusability, storage stability, and ease of needle maintenance make the NPM desirable for the quantitative determination of GLU and LAC from complex biological samples.