Non-enzymatic glucose sensing by enhanced Raman spectroscopy on flexible 'as-grown' CVD graphene.
Unmodified, as-grown few layered graphene on copper substrates have been used for glucose sensing using Raman spectroscopy. Graphene with a stronger 2D band is a better Raman enhancer with significant fluorescence suppression and finer line widths of the Raman signals. The origin of the graphene enhanced Raman spectroscopy (GERS) signal of glucose is attributed to a fractional charge transfer (calculated to be 0.006 using electrochemical parameters) between glucose and graphene aided by a possible π-π interaction. Physiological concentrations of glucose (10-500 mg dl(-1)) in PBS have been used for the study. For each glucose concentration, the spectral reproducibility is within 5-25% as calculated by the relative standard deviation of several measurements. The intensity ratio of the 1122 cm(-1) peak of glucose and the 2D peak of graphene varied linearly with the glucose concentration and can be used as a calibration curve for unknown sample measurements.
Institute of Biophotonics, National Yang-Ming University, 155 Sec-2, Li-Nong Street, Taipei-112, Taiwan. sur@ym.edu.tw.
Surojit
S
Chattopadhyay
Mau-Shiun
MS
Li
Pradip
P
Kumar Roy
C T
CT
Wu
D002021:Buffers; D005947:Glucose / Q000032:analysis* / Q000737:chemistry; D006108:Graphite / Q000737:chemistry*; D013059:Spectrum Analysis, Raman / Q000295:instrumentation*; D013696:Temperature; D014835:Volatilization; D014867:Water / Q000737:chemistry
D002021:Buffers; D014867:Water; D006108:Graphite; D005947:Glucose