PMC:4996384 / 9403-11044 JSONTXT

{"project":"2_test","denotations":[{"id":"27600212-22863116-69481642","span":{"begin":45,"end":47},"obj":"22863116"},{"id":"27600212-24069412-69481643","span":{"begin":48,"end":50},"obj":"24069412"}],"text":"2.4. SPRi Measurements\nAs for previous work [21,22], the SPRi experiments were carried out using a SPR imager apparatus (SPRi-Lab, Horiba Scientific-GenOptics) equipped with an incoherent light source (λ = 635 nm). The reaction chamber consists of a hexagonal reactor PEEK flow cell (~15 µL of volume). The flow cell was connected to PEEK tubing coupled with a degassing system (Alltech, Carquefou, France) and a syringe Cavro pump (Tecan, San Jose, CA, USA). The experiments were performed at 25 °C. All the injections were dispensed using a 500 µL injection loop. The SPR data were acquired using the software furnished by Horiba Scientific-GenOptics. Acquisition of the reflectivity signal, registered with a 12-bit camera, was launched upon stabilization of the baseline. The reflectivity values were averaged over the replicates of each spot series and plotted upon time.\nFor the hybridization experiments, each ssDNA injection (at 1 µM) or AuNPs-ssDNA conjugates injection (at 200 pM) was dispensed via a flow rate of 50µL/mL or an alternating back-and-forth flow mode (15 µL dispensed volume, 10 µL aspirated volume, 50 µL/min flow rate). For biochip recycling, 50 mM NaOH was injected for 8min in order to denature the hybridized complementary strands of DNA and regenerate single stranded DNA on control spots. Concerning the adenosine detection assays, a series of adenosine solutions (from 1 nM to 1 µM) were co-injected with AuNPs-SplitAPT conjugates (200 pM) under the alternating flow. To assess the target-specificity of the sensing system, 1 µM guanosine solution was also co-injected with AuNPs-SplitAPT conjugates (200 pM)."}