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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–H2O2 and luminol–O2 ECL reactions in neutral medium. The sensitized luminol–O2 and luminol–H2O2 reactions were successfully applied for sensing of H2O2, O2, and CO2. With optimized parameters, the determination of H2O2, O2 and CO2 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 H2O2 in clinical H2O2, cosmetic bleach, O2, and CO2 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.

Polymerase chain reaction (PCR) is the gold standard method to amplify deoxyribonucleic acid (DNA) fragments. Several methods have been used to miniaturize and integrate PCR to execute in a microfluidic platform. A continuous-flow-based microfluidic PCR device permits the required rapid thermal cycling and multiplexing, which are hard to realize in a benchtop PCR or microchamber PCR. This work aims to develop a microfluidic PCR platform using a custom-made Internet of Things (IoT)-enabled portable thermal monitoring module. The microfluidic device was fabricated on polymethyl methacrylate (PMMA) using a CO2 laser. Apart from 30 serpentine cycles, the PCR microchannel also had initial denaturation and final elongation regions to enhance the overall amplification. As a proof-of-application, rat GAPDH gene, with a fragment size of 594 base pair, has been amplified on the miniaturized platform. Furthermore, the agarose gel electrophoresis technique was used to separate the DNA molecules validated using a gel-doc system. Subsequently, the acquired results were quantitatively compared with the conventional thermocycler using ImageJ software. Furthermore, this was also validated with electrochemical DNA detection using differential pulse voltammetry (DPV). The results from the smart low-power device showed promising performance for the nucleic acid amplification process while reducing the overall amplification time and achieving benchmarked efficiency.