TY - JOUR
T1 - Probing specific gravity in real-time with graphene oxide plasmonics
AU - Garifullina, Ainash
AU - Bhalla, Nikhil
AU - Shen, Amy Q.
N1 - Funding Information:
We acknowledge nancial support from the OIST Graduate University with subsidy funding from the Cabinet Office, Government of Japan. In addition, the authors would like to thank Dr Casey Gavlin for technical discussions and Mr Laszlo Szikszai, Dr Alexander Badrutdinov, and Mr Alejandro Villar-Briones from OIST for their technical support for the use of various instruments.
Publisher Copyright:
© 2018 The Royal Society of Chemistry.
PY - 2018/1/21
Y1 - 2018/1/21
N2 - Specific gravity (SG), the ratio of the density of a substance to the density of a reference material, is a standard indicator of the concentration of an analyte in a given solution. SG is routinely used for product quality assessment in the food industry. However, currently available commercial SG meters, such as hand-held refractometers and density meters, are highly sensitive to humidity and temperature, and do not allow real-time measurements. For these reasons, SG detection is often time-consuming which leads to unwanted interruptions in food manufacturing processes. Therefore, highly sensitive, label-free, and real-time sensors for the detection of SG are urgently needed for food quality control. In this context, we develop a graphene oxide (GO)-coated gold (Au) surface plasmon resonance (SPR) sensor, for the first time, to measure the SG of food samples in real-time. The SG values of sample solutions are correlated with the refractive indices (RI) of these solutions, which are captured by the SPR measurements, with a sensitivity of 105 SPR response units. Moreover, the use of a GO coating provides a strong enhancement of plasmonic resonances due to its optoelectronic properties, doubling the sensitivity of SPR response units per RI unit (2 × 105) when compared to conventional Au SPR chips (1 × 105). We also validate our sensor performance by measuring the SG in real food samples. Our results demonstrate a highly sensitive, efficient, high throughput, and reproducible approach for SG measurements in food industry settings, and open new opportunities to utilize improved SPR sensor technology for many other label-free analytical sensing applications.
AB - Specific gravity (SG), the ratio of the density of a substance to the density of a reference material, is a standard indicator of the concentration of an analyte in a given solution. SG is routinely used for product quality assessment in the food industry. However, currently available commercial SG meters, such as hand-held refractometers and density meters, are highly sensitive to humidity and temperature, and do not allow real-time measurements. For these reasons, SG detection is often time-consuming which leads to unwanted interruptions in food manufacturing processes. Therefore, highly sensitive, label-free, and real-time sensors for the detection of SG are urgently needed for food quality control. In this context, we develop a graphene oxide (GO)-coated gold (Au) surface plasmon resonance (SPR) sensor, for the first time, to measure the SG of food samples in real-time. The SG values of sample solutions are correlated with the refractive indices (RI) of these solutions, which are captured by the SPR measurements, with a sensitivity of 105 SPR response units. Moreover, the use of a GO coating provides a strong enhancement of plasmonic resonances due to its optoelectronic properties, doubling the sensitivity of SPR response units per RI unit (2 × 105) when compared to conventional Au SPR chips (1 × 105). We also validate our sensor performance by measuring the SG in real food samples. Our results demonstrate a highly sensitive, efficient, high throughput, and reproducible approach for SG measurements in food industry settings, and open new opportunities to utilize improved SPR sensor technology for many other label-free analytical sensing applications.
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U2 - 10.1039/c7ay02423a
DO - 10.1039/c7ay02423a
M3 - Article
AN - SCOPUS:85041194192
VL - 10
SP - 290
EP - 297
JO - Analytical Methods
JF - Analytical Methods
SN - 1759-9660
IS - 3
ER -