Electrogenerated chemiluminescence (ECL) is the production of light via electron transfer reactions between electrochemically produced reagents. ECL-based biosensors use specific biological interactions to recognize an analyte and produce a luminescent signal. Biosensors fabricated with novel biorecognition species have increased the number of analytes detected. Some of these analytes include peptides, cells, enzymes and nucleic acids. ECL biosensors are selective, simple, sensitive and have low detection limits. Traditional methods use ruthenium complexes or luminol to generate ECL. Nanomaterials can be incorporated into ECL biosensors to improve efficiency, but also represent a new class of ECL emitters. This article reviews the application of ruthenium complex, luminol and nanomaterial-based ECL biosensors to making measurements in biological matrices over the past 4 years.

Omega (n)-3 fatty acids are vital to neonatal maturation, and recent investigations reveal n-3 fatty acids serve as substrates for the biosynthesis of specialized pro-resolving lipid mediators (SPM) that have anti-inflammatory and immune-stimulating effects. The role SPM play in the protection against negative maternal-fetal health outcomes is unclear, and there are no current biomarkers of n-3 fatty acid sufficiency. We sought to ascertain the relationships between n-3 fatty acid intake, SPM levels, and maternal-fetal health outcomes. We obtained n-3 fatty acid intake information from 136 mothers admitted for delivery using a food frequency questionnaire and measured docosahexaenoic acid (DHA)-derived SPMs resolvin D1 (RvD1) and RvD2 in maternal and cord plasma. We found significantly elevated SPM in maternal versus cord plasma, and increased SPM levels were associated with at-risk outcomes. We also identified that increased DHA intake was associated with elevated maternal plasma RvD1 (p = 0.03; R2 = 0.18) and RvD2 (p = 0.04; R2 = 0.20) in the setting of neonatal intensive care unit (NICU) admission. These findings indicate that increased n-3 fatty acid intake may provide increased substrate for the production of SPM during high-risk pregnancy/delivery conditions, and that increased maternal plasma SPM could serve as a biomarker for negative neonatal outcomes.

Micromolded carbon paste electrodes are easily fabricated, disposable, and can be integrated into microfluidic devices to fabricate inexpensive sensors and biosensors. In this work, carbon paste microelectrodes were fabricated in poly(dimethylsiloxane) using micromolding techniques and were coupled to a microfluidic channel to fabricate electrogenerated chemiluminescence (ECL) sensors. ECL was generated using both the tris(2,2’‐bipyridyl)ruthenium(II)/tripropylamine system and the hydrogen peroxide/luminol system. For each of these ECL systems, the sensor fabrication method was optimized, along with key experimental parameters (applied voltage, solution flow rate, buffer species and luminol concentration). The limit of detection (S/N=3) for TPrA was approximately 2.4 μM with a linear range of 10–100 μM. For hydrogen peroxide, the LOD was approximately 11 μM and the electrodes gave a linear response between 30 μM and 200 μM hydrogen peroxide. Electrodes containing glucose oxidase were fabricated using this new method, demonstrating that glucose could be indirectly detected via generation of hydrogen peroxide by the enzymatic reaction at the micromolded biosensor.

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