DNA-Modified Graphene Oxide Supported on a Fire-Resistant Hydroxyapatite Paper for Timely and Reliable Fire Warning

The traditional fire alarm sensors suffer from sluggishfire warnings.Recently, graphene oxide (GO)-based sensors have attracted much attentiondue to their ultrafast fire warning. There are two major challenges:(i) the duration time of fire warning is short due to poor flame retardancyof GO and (ii) the response temperature of the GO sensor is high dueto the abundant oxygen-containing groups. This work reports the single-strandeddeoxyribonucleic acid (ssDNA)-modified GO supported on the hydroxyapatite(HA) nanowire paper. The ssDNA molecules have an action of intumescentflame retardancy, which effectively improves the flame retardancyof GO. Moreover, the thermal degradation of nitrogenous base of ssDNAcauses nitrogen doping in GO. Concomitantly, the thermal reductionof GO is promoted, and some oxidative groups are removed. As a result,the period of fire warning of GO increases up to 180 s, and the responsetemperature decreases to as low as 159 & DEG;C. Besides, the HA paperwith intrinsic fire resistance ensures the structural integrity ofssDNA-DNA in the flame, contributing to the steady workingof the composite paper. This work highlights the critical roles ofbiomolecules and inorganic materials in synergistically regulatingfire warning performance of GO.