Label-Free Biochemical Analytic Method for the Early Detection of Adenoviral Conjunctivitis Using Human Tear Biofluids

Abstract

Cell culture and polymerase chain reaction are currently regarded as the gold standard for adenoviral conjunctivitis diagnosis. They maximize sensitivity and specificity but require several days to 3 weeks to get the results. The aim of this study is to determine the potential of Raman spectroscopy as a stand-alone analytical tool for clinical diagnosis of adenoviral conjunctivitis using human tear fluids. A drop-coating deposition surface enhanced Raman scattering (DCD-SERS) method was identified as the most effective method of proteomic analysis in tear biofluids. The proposed DCD-SERS method (using a 2-μL sample) led to Raman spectra with high reproducibility, noise-independence, and uniformity. Additionally, the spectra were independent of the volume of biofluids used and detection zones, including the ring, middle, and central zone, with the exception of the outer layer of the ring zone. Assessments with an intensity ratio of 1242-1342 cm(-1) achieved 100% sensitivity and 100% specificity in the central zone. Principal component analysis assessments achieved 0.9453 in the area under the receiver operating characteristic curve (AUC) as well as 93.3% sensitivity and 94.5% specificity in the central zone. Multi-Gaussian peak assessments showed that the differences between these two groups resulted from the reduction of the amide III α-helix structures of the proteins. The presence of adenovirus in tear fluids could be detected more accurately in the center of the sample than in the periphery. The DCD-SERS technique allowed for high chemical structure sensitivity without additional tagging or chemical modification, making it a good alternative for early clinical diagnosis of adenoviral conjunctivitis. Therefore, we are hopeful that the DCD-SERS method will be approved for use in ophthalmological clinics in the near future.

A low-cost, monometallic, surface-enhanced Raman scattering-functionalized paper platform for spot-on bioassays

“…Clinical situations often involve long waiting periods to receive analytical results through conventional analytical techniques such as enzyme-linked immunosorbent assay (ELISA), direct immunofluorescence assay (IFA), and polymerase chain reaction (PCR). Although rapid diagnosis is imperative for prescription of appropriate treatments to prevent further infections of viral or bacterial infection-driven conjunctivitis and corneal damage, conventional time-consuming procedures are still used in ophthalmological clinics [29]. Therefore, we introduce the fabrication of a monometallic SERS-functionalized paper platform using a mixture of AuNPs and viscous ink based on a screen-printing technique.…”

Rapid label-free identification of Klebsiella pneumoniae antibiotic resistant strains by the drop-coating deposition surface-enhanced Raman scattering method

“…The mean drying time of the K. pneumoniae colonies was b20 min at room temperature. Since the DCD-SERS procedure resulted in a coffee ring phenomenon [32] due to Marangoni flow during evaporation, Raman spectra at both the central and ring zones must be analyzed and compared [18,33]. All groups showed clear perimeters and some substance at the middle zones.…”

“…For this molecule, the correlation coefficient was 0.98 within the range of 0.1 nM to 1 mM. The enhancement factor (EF) of the Platypus® gold substrate was roughly calculated as described [18][19][20][21]. Briefly, the EF was calculated as the difference in Raman intensities between two different substrates as follows:…”

“…These signals correspond to spectroscopic fingerprints that reflect the overall molecular composition of a sample [17]. Our research group has employed this sensing technology in various biosensing applications [18][19][20][21][22][23][24][25][26][27][28].…”

“…However, the method sometimes failed due to high sample heterogeneity. Therefore, we applied an experimental protocol based on drop-coating deposition surface-enhanced Raman scattering (DCD-SERS) [18] and combined it with a machine-trained multivariate statistical method for rapid subtyping of quinolone-resistant K. pneumoniae strains (Scheme 1). The DCD-SERS procedure was evaluated using three K. pneumoniae strain subtypes, ATCC70063 (control), ST11, and ST15, all of which were genetically verified by multilocus sequencing typing (MLST).…”