abstract
In the present work, we have fabricated silver nanoprism (AgNPrs)/silicon nanoparticle (SiNPs) hybrid arrays for highly sensitive detection of biomolecules via surface-enhanced Raman spectroscopy (SERS) technique. SiNPs having 7 to 37 nm in size and with phosphorous doping varying from 1 x 1019 to 1 x 1020 cm-3 were synthesized in nonthermal plasma synthesis. SiNPs were further immobilized on glass substrates using spin-coating, followed by deposition of AgNPrs using the drop-casting method. SERS studies showed that AgNPrs/SiNPs hybrid arrays exhibit substantial amplification of fingerprint bands of rhodamine 6G (R6G) compared to bare silicon as the reference. Raman signal intensity was found to be dependent on the size of SiNPs, with the largest nanoparticles exhibiting the highest SERS enhancement. In addition, an increase in phosphorous doping concentration was found to reduce R6G peak intensities. AgNPrs/SiNPs hybrid arrays showed excellent stability over time and high spot-to-spot reproducibility as well. Moreover, hybrid arrays enabled DNA detection through intense vibrational modes of human genomic DNA, with a lower detection limit of 1.5 pg/mu L; indicating that AgNPrs/SiNPs sensors can serve as a reliable and cost-effective biosensing platform for rapid and label-free analysis of biomolecules.
keywords
SERS SUBSTRATE; LIGHT-EMISSION; SINGLE; MICROSPHERES; ADSORPTION; PLATFORM; ARRAYS
subject category
Spectroscopy
authors
Daoudi, K; Columbus, S; Falca, BP; Pereira, RN; Peripolli, SB; Ramachandran, K; Kacem, HH; Allagui, A; Gaidi, M
Groups
Projects
CICECO - Aveiro Institute of Materials (UIDB/50011/2020)
CICECO - Aveiro Institute of Materials (UIDP/50011/2020)
Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)
acknowledgements
The authors would like to acknowledge financial support from the University of Sharjah (grant No. 2102143096) . This work was developed within the scope of the projects I3N, UIDB/50025/2020 & UIDP/50025/2020, and CICECO, UIDB/50011/2020, UIDP/50011/2020 & LA/P/0006/2020, financed by national funds through the FCT/MEC (PIDDAC) . R.N.P. We like to extend thanks to Maria Rosario Correia for the useful discussions. The authors wish to thank Mr. Javad B.M Parambath, Centre for Advanced Materials Research, for his assistance in XPS analysis of SERS sensors.