Sensitive label-free detection of bilirubin in blood using boron nitride-modified nanorod arrays as SERS substrates

Hyperbilirubinemia refers to an increase in bilirubin (BR) levels and is a serious health concern; in severe cases, hyperbilirubinemia can lead to the death of newborns infants within the first month. Traditional analytical technologies normally involve complex sample pretreatment procedures yet present unsatisfactory detection limits for BR levels. In this study, we developed a recyclable surface-enhanced Raman scattering (SERS) substrate by modifying functional boron nitride (M-BN) monolayer nanosheets on silver nanoarrays (Ag NRs/M-BN) for label-free detection of BR in complex biological samples. Modification of M-BN to silver nanoarrays (Ag NRs) significantly improved the detection sensitivity and long-term stability of the substrate due to the strong surface adsorption ability and thermal stability of M-BN. The limit of detection (LOD) of BR in blood obtained from the Ag NRs/M-BN was as low as 2.5 × 10−8 M, which was attributed to its superior affinity for hydrophobic BR molecules. The spiked blood samples were practically tested with recovery values of around 80 %, and relative standard deviations (RSD) were less than 15 %. The results, combined with the excellent reusability of the as-developed substrates, indicated that the Ag NRs/M-BN substrate provides a simple yet promising platform for nondestructive detection of BR.