Smartphone-based chemiluminometric hybridization assays and quantitative competitive polymerase chain reaction

The present report introduces the smartphone as a simple, low-cost detector/imager for chemiluminometric hybridization assays and quantitative competitive polymerase chain reaction (QCPCR). In QCPCR the amplification products from the target and the competitor DNA have identical sizes but differ in a short sequence flanked by the primers. The products are hybridized with their cognate oligonucleotide probes, captured on microtiter wells and detected via an enzyme-catalyzed chemiluminogenic reaction using the smartphone as a detector/imager. We provide, for the first time, data on: (a) the detectability, analytical range and reproducibility of smartphone-based chemiluminometric hybridization assays of double stranded amplification products, (b) the comparison of smartphone-based detection with a conventional digital camera and a luminometer, and (c) the detectability, analytical range and reproducibility of smartphone-based QCPCR in terms of the number of copies of input target sequences in the sample prior to amplification. The limits of detection of the DNA hybridization assay based on the smartphone, digital camera and luminometer were 1.6, 2.4 and 1 pmol L^-1. Smartphone-based QCPCR showed an analytical range from 137 to 9 × 10⁵ copies of target DNA.