Infused self-assembly on Langmuir-Blodgett Film: Fabrication of highly efficient SERS active substrates with controlled plasmonic aggregates

A facile procedure towards the fabrication of highly reproducible, large area surface-enhanced Raman scattering (SERS) active substrates through integration of Langmuir-Blodgett and self-assembly technique has been reported. The plasmonic architectures of the substrates can be tuned at will to control the hot spots and hence the overall enhancements of SERS signal. The as-prepared substrates of classes "A" and "B" incubated in gold nanocolloids show their respective efficacies as efficient SERS sensing scaffolds for detecting 4-MPy molecule at ultrasensitive concentrations. Moreover, these substrates are unique in their kinds, where explicit or concomitant presence of protonated and deprotonated forms of 4-MPy can be detected at trace concentrations. The substrates also exhibit remarkable spectral reproducibility and show early promise to overcome the "SERS uncertainty principle". To our knowledge, this genre of SERS active substrates with facile control over plasmonics, is the first report of its kind and are expected to provide new direction towards successful fabrication of the next generation SERS sensing platforms.