Designing Electrochemical Biosensing Platforms Using Layered Carbon-Stabilized Porous Silicon Nanostructures

Keying Guo, Maria Alba, Grace Pei Chin, Ziqiu Tong, Bin Guan, Michael J. Sailor, Nicolas H. Voelcker*, Beatriz Prieto-Simón*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Porous silicon (pSi) is an established porous material that offers ample opportunities for biosensor design thanks to its tunable structure, versatile surface chemistry, and large surface area. Nonetheless, its potential for electrochemical sensing is relatively unexplored. This study investigates layered carbon-stabilized pSi nanostructures with site-specific functionalities as an electrochemical biosensor. A double-layer nanostructure combining a top hydrophilic layer of thermally carbonized pSi (TCpSi) and a bottom hydrophobic layer of thermally hydrocarbonized pSi (THCpSi) is prepared. The modified layers are formed in a stepwise process, involving first an electrochemical anodization step to generate a porous layer with precisely defined pore morphological features, followed by deposition of a thin thermally carbonized coating on the pore walls via temperature-controlled acetylene decomposition. The second layer is then generated beneath the first by following the same two-step process, but the acetylene decomposition conditions are adjusted to deposit a thermally hydrocarbonized coating. The double-layer platform features excellent electrochemical properties such as fast electron-transfer kinetics, which underpin the performance of a TCpSi-THCpSi voltammetric DNA sensor. The biosensor targets a 28-nucleotide single-stranded DNA sequence with a detection limit of 0.4 pM, two orders of magnitude lower than the values reported to date by any other pSi-based electrochemical DNA sensor.

Original languageEnglish
Pages (from-to)15565-15575
Number of pages11
JournalACS applied materials & interfaces
Issue number13
StatePublished - 6 Apr 2022
Externally publishedYes


  • controllable surface chemistry
  • dual-surface functionality
  • electrochemical biosensor
  • layered nanostructures
  • porous silicon


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