Fig. 1: Preparation of two nanomaterials for MNALCI.

a Characterization of gold nanoshell (GNS): SEM showing relative uniform size distribution ~150 nm in diameter and the rough surface feature (n ≥ 5 randomly selected). b TEM images (n ≥ 3 randomly selected) and EDX analysis of the elemental distribution with O (azure), Si (red) and Au (yellow), proving the core-shell nanostructure. c Characterization of porous silicon nanowires: cross-section SEM image of the etched Si wafer showing high density nanowires forest (n ≥ 5 randomly selected). (inset), TEM image showing highly porous nature of individual nanowires (n ≥ 3 randomly selected). d Schematic of GNS and SiNW-assisted LDI measurement. e Comparison of typical LDI signals of a representative serum sample mixed with GNS, SiNW and CHCA.