Single-Particle Study: Refractive Index Sensitivity of Localized Surface Plasmon Resonance Inflection Points in Mesoporous Silica-Coated Gold Nanorods

허성은,하지원 한국바이오칩학회 2022 BioChip Journal Vol.16 No.2

Gold nanorods coated with a mesoporous silica shell (AuNRs@mSiO 2 , core@shell) have been in the employment for various bioapplications, including drug delivery and photothermal cancer therapy. Nevertheless, limited studies have been conducted on AuNRs@mSiO 2 for their biosensing applications that use a refractive index (RI)-based localized surface plasmon resonance (LSPR). In this study, the LSPR detection sensitivity of individual AuNRs@mSiO 2 with two distinctive core sizes, but the same aspect ratio of 3, was presented at LSPR inflection points (IFs) according to RI variations of the surrounding environment. The RI sensitivity at the homogeneous LSPR IF located on the low-energy side was higher than the wavelength shifts in the conventional LSPR maximum peak. Moreover, single AuNRs@mSiO 2 having a smaller core size exhibited better RI sensitivity at the IFs of LSPR. Thus, we presented a better understanding of the RI-based detection sensitivity in single AuNRs@mSiO 2 at LSPR IFs for developing LSPR biosensors.

In-direct localized surface plasmon resonance (LSPR)-based nanosensors for highly sensitive and rapid detection of cortisol

Jeon, Jinwoo,Uthaman, Saji,Lee, Jiyoung,Hwang, Hyejin,Kim, Gibum,Yoo, Pil J.,Hammock, Bruce D.,Kim, Christine S.,Park, Yeon-Su,Park, In-Kyu Elsevier 2018 Sensors and actuators. B, Chemical Vol.266 No.-

<P><B>Abstract</B></P> <P>Over-secretion of cortisol from the adrenal cortex is closely related to acute and chronic stress; thus, rapid and sensitive detection of cortisol in serum is of critical importance for preventing the progression of stress-related diseases. The binding of a biological molecule to the surface of metallic nanoparticles changes the local refractive index and in turn induces a shift in the localized surface plasmon resonance (LSPR) wavelength. Utilizing this phenomenon, we designed a novel disposable LSPR-based cuvette-type sensor for detecting cortisol in serum. The developed cuvette-type nanosensor consists primarily of an assembly of plastic unit sensors coated with gold nanoparticles on a single layer wherein cortisol-conjugated bovine serum albumin (BSA) is immobilized. In this system, a redshift in LSPR wavelength is induced by the binding of cortisol antibody onto cortisol-conjugated BSA immobilized on a gold nanoparticle surface in the nanosensor. In a competitive assay, the nanosensor could rapidly detect cortisol in both a PBS solution and serum (within 20 min) at concentrations ranging from 1 to 10,000 ng/mL (2.759–3 × 10<SUP>3</SUP> nmol/L), which is comparable to conventional enzyme-linked immunosorbent assay (ELISA) which typically requires longer than 4 h and complex sample preparation. Thus, we demonstrated that the LSPR-based nanosensor system developed in this study can provide a useful toolkit for a rapid, highly sensitive and reliable detection of cortisol hormone in a commercially available manner.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Novel disposable LSPR-based cuvette-type sensor for detecting cortisol in serum. </LI> <LI> Rapid, convenient, and sensitive method for detecting cortisol hormone in serum. </LI> <LI> Detect cortisol in both PBS solution and serum within 20 min at concentrations ranging from 1 to 10,000 ng/mL. </LI> </UL> </P>

1LJ-4 Strategies for enhancing the sensitivity of plasmonic nanosensors

김동환 한국공업화학회 2017 한국공업화학회 연구논문 초록집 Vol.2017 No.1

Recent progress on plasmonic biosensors has enabled LSPR-shift assay with single nanoparticles. Single-nanoparticle plasmonic sensors are particularly attractive because of small sample volume required, better signal-to-noise resolution, and lower limits of detection. However, variations in the corresponding LSPR-shifts to surrounding refractive index change (Δn) among structurally different particles have not fully studied. Hence, we discuss the LSPR scattering peak wavelength distribution of individual gold nanoparticles, the effect of this variation to the sensitivity of LSPR-based sensors, and methods to minimize the variations in the LSPR responses among different particles. This promising plasmonic biomolecular assay on the nanoarray should find application in parallel screening of nucleic acid and protein profiles and will compete with current microarrays. Finally, most recent development on a plasmonic dimer that utilizes plasmonic coupling will be also discussed.

Plasmonic hybrid nanosystems for molecular detection based on localized surface plasmon resonance

이승현 한국공업화학회 2015 한국공업화학회 연구논문 초록집 Vol.2015 No.0

Localized surface plasmon resonance (LSPR) describes the collective oscillation of free electrons that occurs when light is incident on a noble metal nanoparticle. LSPR results in strong optical extinction which can be tuned throughout the visible and near-infrared wavelengths by adjusting the particle’s size and shape. The LSPR spectral extinction peak is sensitive to the surrounding media’s refractive index, which allows LSPR-active nanostructures to act as transducers in label-free biosensors. In particular, hybrid nanosystem with plasmonic nanoparticles and carbon nanomaterials have been employed to SERS-active substrates for environmental and nanomedicine applications. The carbon- plasmonic hybrid nanostructures demonstrate a unique technique for molecular detection and it may support to expand SERS-active substrate technology more broadly.

Nanoplasmonic biosensors for detection/amplification of dual bio-signatures of circulating tumor DNA (ctDNA)

김수현,( Nguyen Hung Anh ),심상준 한국공업화학회 2018 한국공업화학회 연구논문 초록집 Vol.2018 No.0

Circulating tumor DNA (ctDNA) are promising biomarker for noninvasive cancer assay in tumor-specific mutation and methylation. However, previous methods for ctDNA detection have limitation in genetic mutations. Here we present a strategy for ultrasensitive detection of tumor-specific mutations and methylation of ctDNA based on localized surface plasmon resonance (LSPR) and the coupling plasmon mode of gold nanoparticles (AuNPs). Peptide nucleic acid (PNA) is used as a probe to capture and enrich ctDNA. The exposure of PNA-probed AuNPs to target ctDNA generates the primary response of LSPR-peak shift. Immunogold colloids are exploited as methylation detectors and plasmon coupling enhancers for secondary response. LSPR-peak shift is increased approximately 107% upon immunogold colloids binding to two methylcytosines, compared to the primary response. These results demonstrate that the sensor can simultaneously detect the hot-spot mutation and epigenetic changes on the ctDNA.

Nanoplasmonic biosensors for detection of circulating tumor DNA(ctDNA) in genetic and epigenetic condition

김우현,( Nguyenhunganh ),심상준 한국공업화학회 2016 한국공업화학회 연구논문 초록집 Vol.2016 No.1

Circulating tumor DNA (ctDNA) are promising biomarker for noninvasive cancer assay in tumor-specific mutation and methylation. However, previous methods for ctDNA detection have limitation in genetic mutations. Here we present a strategy for ultrasensitive detection of tumor-specific mutations and methylation of ctDNA based on localized surface plasmon resonance (LSPR) and the coupling plasmon mode of gold nanoparticles (AuNPs). Peptide nucleic acid (PNA) is used as a probe to capture and enrich ctDNA. The exposure of PNA-probed AuNPs to target ctDNA generates the primary response of LSPR-peak shift. Immunogold colloids are exploited as methylation detectors and plasmon coupling enhancers for secondary response. LSPR-peak shift is increased approximately 107% upon immunogold colloids binding to two methylcytosines, compared to the primary response. These results demonstrate that the sensor can simultaneously detect the hot-spot mutation and epigenetic changes on the ctDNA.

Detection of ApoE4-mediated beta amyloid42 aggregation based on localized surface plasmon resonance biosensor

김한비,강민경,심상준 한국공업화학회 2015 한국공업화학회 연구논문 초록집 Vol.2015 No.1

Alzheimer’s disease (AD), which is the most common form of dementia, is characterized by a widespread functional disturbance of the human brain. From the statistical report in 2013, just over a tenth of people in the over-65 age group have the disease in United States. In the over-85s, the proportion goes up to about a third. Brain plaque deposition in the form of beta amyloid (Aβ) is a pathological hallmark of AD. The Aβ deposition is facilitated by an isoform of Apolipoprotein E4 (ApoE4), which is a dominant genetic risk factor of AD. Here, we present a nanoplasmonic biosensor to detect the dynamics of ApoE4-mediated Aβ aggregation. This sensor is based on the localized surface plasmon resonance (LSPR) of a single gold nanoparticle. In this sensor, ApoE4 is exploited as an inducer of Aβ42 aggregation. According to the LSPR spectra, the aggregation of Aβ42 is more specific and rapid than that of Aβ40. In addition, a detection limit of 50 μM for Aβ42 can be obtained corresponding to the 12.5 nm LSPR-peak shift, which is in line with the requirement for clinical detection. This is the first platform for the real-time detection of Aβ aggregation, mimicking the biological conditions, which can be used to investigate AD directly in the future.

금 나노입자의 LSPR효과를 이용한 열감응성 색센서 제작

손형진,홍건영,홍정현,김지수,김영훈 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.1

열감응성 고분자는 특정 온도에서 분자 내 친수성기와 소수성기의 작용이 달라져 고분자 사슬이 가역적으로 수축·팽창하는 부피 상전이를 보이는 물질이다. 대표적인 열감응성 고분자인 폴리나이팜(PNIPAM)은 사람의 체온에 근접한 32°C에서 부피 상전이를 보인다. 본 연구에서는 라디칼 중합을 통해 PNIPAM을 하이드로겔 형태로 합성, 국소 표면 플라즈몬 공명(LSPR) 효과를 보이는 금 나노입자를 직접 환원시켜 색센서를 제작하였고, 중합 시 도입한 공단량체의 특성에 따른 하이드로겔의 LCST 변화를 확인했다. 본 연구를 통해 온도 변화를 쉽게 파악할 수 있는 색센서 제작을 기대할 수 있다.

Structure-controllable Plasmonic Nanostructures with the Biomolecular DNA

양수지,( Xing-yi Ma ),심상준 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.0

Plasmonic nanomaterials reveal noble optical properties for nextgeneration biosensors. Notably, an individual nanoparticle analysis can yield unique target information by LSPR. Based on the lab-on-a-particle technology, the next-generation biosensor is revolutionary for endpoint detection (single or multiplex), and can be functionally extended to biological phenomena monitoring. We developed a new nanoplasmonic sensor to attain label-free, real-time, and cost-effective monitoring of the molecular interactions based on LSPR by analysis of epigenetics-driven transcriptional repression of DNA methylation, binding efficiency of normal polymerase with mutated DNA, and then normal promoter with mutated protein obtained from cancer cells.

Rapid detection of alzheimer’s disease by APOE4-mediated β-amyloid aggregation using localized surface plasmon resonance biosensor

강민경,심상준 한국공업화학회 2014 한국공업화학회 연구논문 초록집 Vol.2014 No.1

Brain plaque deposition in the form of beta amyloid (Aβ) is a pathological hallmark of Alzheimer’s disease (AD). Furthermore, the increment of Aβ deposition is associated with an isoform of Apolipoprotein E4, a dominant genetic risk factor of AD. Here, we present a nanoplasmonic biosensor to detect the dynamics of ApoE4-mediated Aβ aggregation. Based on localized surface plasmon resonance (LSPR) spectra, the rate of Aβ42 aggregation increases more rapidly than that of Aβ40. In this sensor, ApoE4 is exploited as Aβ42 detector and plasmon resonance promoter. In addition, a detection limit of Aβ42 at 50 μM can be obtained corresponding to the LSPR-peak shift of 12.5 nm. This is the first biomimetic platform for measurements of Aβ aggregation in biological conditions, which can be used to investigate AD directly in the future.