Lung cancer is the leading cause of cancer-related death in the world. Early diagnosis has great significance for the survival of patients with lung cancer. In this paper, attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy combined with chemometrics was used to study the serum samples from patients with lung cancer and healthy people. The results of spectral band area comparison showed that the concentrations of protein, lipid and nucleic acids molecules in serum of patients with lung cancer were increased compared with those in healthy people. The original spectra were preprocessed to improve the accuracy of principal component regression (PCR) and partial least squares-discriminant analysis (PLS-DA) models. PLS-DA results for first derivative spectral data in nucleic acids (1250-1000cm^-1) band showed 80% sensitivity, 91.89% specificity and 87.10% accuracy with high Rc2 of 0.8949 and Rv2 of 0.8153, low RMSEC of 0.3136 and RMSEV of 0.4180. It is shown that ATR-FTIR spectroscopy combined with chemometrics might be developed as a simple method for clinical screening and diagnosis of lung cancer.

Optogenetic technology has great potential for its application in neuroscience research. The integrated optoelectrode has high spatiotemporal resolution. However, noise due to high-density integration is still a factor affecting the accuracy of bio-signal detection. In this article, we investigate the sources and mechanisms of light-emitting diode (LED)-induced artifacts in the integrated optoelectrode based on an InGaN/GaN LED epitaxial wafer grown on a sapphire substrate. We demonstrate that the main sources of LED-induced artifacts include electromagnetic radiation interference and the photoelectrochemical (PEC) effect under illumination. To reduce the LED-induced artifacts and other additional noise, the differential microelectrode (D-ME) with multiple noise windows was integrated on the optoelectrode. The differential results show that the integrated optoelectrode with the D-ME can reduce the peak-to-peak voltage (Vpp) of the LED-induced artifact from more than 500 μV to nearly 130 μV. This improvement is achieved without adding extra fabrication steps and contributes to an enhanced effective signal-to-noise ratio (SNR) in optogenetic applications.