A Portable 3-D Printed Electrochemiluminescence Platform With Pencil Graphite Electrodes for Point-of-Care Multiplexed Analysis With Smartphone-Based Read Out

Herein, a portable 3-D printed miniaturized bipolar electrode-electrochemiluminescence (BPE-ECL) platform is presented. The platform has a smartphone-enabled read-out method for ECL signal analysis, a 9-V Hi-watt battery for power supply, and graphitized mesoporous carbon/multiwalled carbon nanotube (GMC/MWCNT) nanomaterial-modified pencil graphite electrodes (PGEs) as bipolar and driving electrodes. The nanomaterial-modified pencil graphite bipolar electrode (PG-BPE) showed great electrocatalytic activity toward luminol-H 2 O 2 and luminol-O 2 ECL reactions in neutral medium. The sensitized luminol-O 2 and luminol-H 2 O 2 reactions were successfully applied for sensing of H 2 O 2 , O 2 , and CO 2 . With optimized parameters, the determination of H 2 O 2 , O 2 and CO 2 can be in the linear range of 0.08- 5000~\mu \text{M} , 0.3-9 mg/L, and 0.6-9 mg/L with the detection limit of 0.069~\mu \text{M} , 0.15 mg/L, and 0.45 mg/L. As a prototype application, quantitative detection of glucose has been carried out with a modified PGE anchored with GOx (GMC/MWCNT at GOx). The prepared electrode was analyzed for physicochemical and microscopic characterizations. The modified PGE showed an excellent ability to detect the glucose in a linear range of 1~\mu \text{M} -10 mM with a detection limit of 0.31~\mu \text{M} . Finally, the platform was subjected to real sample analysis of H 2 O 2 in clinical H 2 O 2 , cosmetic bleach, O 2 , and CO 2 in lake water and tap water and glucose in human blood serum samples. The results indicated that the proposed platform offered excellent reliability, accuracy, and amenable to be used for multiple point-of-care biochemical analysis.