Innovative Engineering of Sorets on Photonic Crystal to Augment Sensing Technologies

Dr. Sai Sathish Ramamurthy (STAR Lab, SSSIHL) in a trilateral collaboration with Dr. Chandramouli Subramaniam (Nanostructured Material Lab, IIT-Bombay) and Dr. Shivakiran Bhaktha (Photonic Systems Laboratory, IIT-Kharagpur) has published a new paper in Nanophotonics (Walter de Gruyter publication) demonstrating unusual ‘photoplasmonic’ effects (as they call it in the article) with the use of gold nano-assembly termed ‘sorets’ and Nd2O3 nanorods. The unavoidable losses in the gold nanoparticles are overcome with these functional metasurfaces in photonic crystal-coupled emission (PCCE) platform developed by the team in the year 2020, thereby demonstrating outstanding performance of the subject platform for several sensor applications.

Identifying the Issue

• Sensors are widely used in industrial processes, monitoring community well-being, homeland safety, criminalistics, environmental health supervision and point-of-care diagnostics
• Nanomaterials made of metals (generally called plasmonic materials) are throughout-the-world used in the evolution of sensor technology systematization. However, their accurate potential is beleaguered by inevitable inherent Ohmic losses that encumber the functional performance of any sensing platform
• Therefore, there is constant need for novel synthetic routes and advanced material platforms for global market sensor industries, using nanochemistry-based novel methods

Objective of the Research

• Ascertaining the ground elemental causes which leads to unproductive Ohmic losses in terms of basic physico-chemical aspects of the individual nano-constructs
• Discovering a frugal & viable technological solution to abate/preclude the Ohmic losses and recuperate the performance of gold nanomaterials, consequently demonstrating a translational approach to offer sensor-based industries with materials with grander efficiencies
• Refining the overall sensitivity and specificity of photoplasmonic sensor platform using cut-rate metal-dielectrics in comparison with cost intensive and hazardous nano-sensor techniques

Who should read this?

Anyone in industry, working directly or indirectly on advanced sensor technologies or sensing related know-hows including, security, reconnaissance, specialist (intensive) care units, environmental safety monitoring mechanisms, therapeutic technologies and disease diagnostics. Further this article will be extremely useful to researchers currently faced with the problem of ‘Losses’ in metamaterials dependent on plasmonic nanoparticles.

“Photoplasmonics”– A blossoming, rapid & realistic solution for the snags in biosensor technologies

• The novel nano-engineering strategies for diverse applications in optics and nano-bioengineering domains are discussed in this work
• In spite of copious electron densities of ≈ 5.9 × 1022 cm−3, excellent biocompatibility, structural tunability and utility in numerous biosensors, so far the quenching phenomenon in gold nanoparticles has remained an unescapable caveat
• Although sharp-edged nanostars and decorated nanohybrids have been explored in the past, the enhancement factor has been modest at 200-fold. The PCCE platform developed in this work with the use of gold sorets and high refractive index Nd2O3 ‘Huygens sources’ demonstrated unprecedented >1500-fold enhancement factor

Key Features and Benefits

• Use of judicious hybrid metal nano-assembly – dielectric nanorods assemblage.
• Experimental demonstration of suppressed quenching and >1500-fold PCCE enhancement.
• The multifold ‘gap-based antenna’ and ‘lightning-rod’ effects generated by the nano-assemblies and nanorods that sustain multitudinous hotspots catering to excellent sensitivity of PCCE platform
• The proposed hybrid methodology is useful in disease diagnostics for monitoring early stages of the disease and also aid in the fabrication of smart sensor chips for use in Point-of-Care (POC) devices

Impact

• The collective and coherent coupling between localized Mie and delocalized Bragg plasmons (of sorets), dielectric plasmons (of Nd2O3), highly confined & intense Bloch surface waves (of PCCE platform) aided in realization of dequenched, as well as amplified > 1500-fold enhancements at the photoplasmonic nanocavity interface, thereby addressing the quenching predicament
• The PCCE platform is expected to find immediate deployment for real-time monitoring of health and hazardous in environment. This study presents itself as a milestone to explore a plethora of exciting disruptive nano-engineering with the aid of different permutations and combinations of nanomaterials of different geometry and number, chosen from the Periodic Table. We anticipate the crucial role of machine learning and data science pertaining to materials properties in this regard.
• The proposed technology is a jumping-off point for sensor-based industrial establishments or market seeking such devices with augmented sensitivity. The high sensitivity aids in early disease diagnostics, ecological safety and bio-nano-engineering and related applications
• The rapid, cost-effective and simple plasmon mixing strategy used in the photoplasmonic platform with advanced nano-engineering are of immense benefit for low- and middle-income countries, in resource-limited settings and bottom of the pyramid.

Team

Seemesh Bhaskar,^† Pratyusha Das,^‡ Maku Moronshing,^¶ Aayush Rai,^† Chandramouli Subramaniam,^¶ Shivakiran Bhaktha B. N. ^‡ and Sai Sathish Ramamurthy^†.

^†STAR Laboratory, Department of Chemistry, CRIF, Sri Sathya Sai Institute of Higher Learning, Prasanthi Nilayam, Puttaparthi, Anantapur, Andhra Pradesh 515134, India.
^¶Nanostructured Material Lab, Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, Maharashtra, INDIA.
^‡Photonic Systems Laboratory, Department of Physics, Indian Institute of Technology Kharagpur, Kharagpur, India -721302

Paper Published in: Nanophotonics

Title: Photoplasmonic assembly of dielectric-metal, Nd2O3-Gold soret nanointerfaces for dequenching the luminophore emission

Read Paper Here: https://doi.org/10.1515/nanoph-2021-0124