Abstract: Provided herein is a biosensor for conformation and secondary structure analysis, notably for the direct non-invasive qualitative secondary structure analysis of a single selected protein within a complex mixture, as e.g. a body fluid, by vibrational spectroscopic methods. For the analysis it is not required that the selected substance be isolated, concentrated, or pretreated by a special preparative procedure.

Abstract: Provided herein is a biosensor for conformation and secondary structure analysis, notably for the direct non-invasive qualitative secondary structure analysis of a single selected protein within a complex mixture, as e.g. a body fluid, by vibrational spectroscopic methods. For the analysis it is not required that the selected substance be isolated, concentrated, or pretreated by a special preparative procedure.

Abstract: The invention provides a method that gives direct information about the intervention of a potential drug on the secondary structure distribution of a targetbiomolecule, i.e., for a disease with misfolded protein, such as neurodegenerative diseases in a complex body fluid. The secondary structural change is monitored by vibrational spectroscopy. The method can be applied for prescreening of drug candidates for targeting of specific biomolecules. The effect of the drug on the secondary structure distribution is monitored label-free in real time and provides thereby direct information about the efficacy of the potential drug.

Abstract: Provided herein is a biosensor for conformation and secondary structure analysis, notably for the direct non-invasive qualitative secondary structure analysis of a single selected protein within a complex mixture, as e.g. a body fluid, by vibrational spectroscopic methods. For the analysis it is not required that the selected substance be isolated, concentrated, or pretreated by a special preparative procedure.

Abstract: Provided herein is a biosensor for conformation and secondary structure analysis, notably for the direct non-invasive qualitative secondary structure analysis of a single selected protein within a complex mixture, as e.g. a body fluid, by vibrational spectroscopic methods. For the analysis it is not required that the selected substance be isolated, concentrated, or pretreated by a special preparative procedure.

Abstract: The invention provides an infrared detection system for conformation and secondary structure analysis, notably for the direct non-invasive qualitative secondary structure analysis of a single selected protein within a complex mixture, as e.g. a body fluid, by vibrational spectroscopic methods utilizing a quantum-cascade laser. For the analysis it is not required that the selected substance be isolated, concentrated, or pretreated by a special preparative procedure. A difference-spectrum between the unbound and antibody-bound protein of interest is performed by which the much larger background absorbance is cancelled. The presented quantum-cascade laser set-up provides sufficient S/N and stability to subtract the several orders of magnitude larger background absorbance.

Abstract: The invention provides a combined immuno-infrared assay for the differential diagnosis and sub classification of Alzheimer's disease into different disease stages. The method can be applied for assured disease diagnostics and patient stratification. The assay considers the label-free detection of the change within the Amyloid-beta peptide and Tauprotein secondary structure distribution in bodily fluids. This secondary structure change from native to ?-sheet enriched isoforms appears years before clinical disease manifestation. Now, the combined method utilizes this shift for diagnostics based on liquid biopsies.

Abstract: The invention provides a method that gives direct information about the intervention of a potential drug on the secondary structure distribution of a targetbiomolecule, i.e., for a disease with misfolded protein, such as neurodegenerative diseases in a complex body fluid. The secondary structural change is monitored by vibrational spectroscopy. The method can be applied for prescreening of drug candidates for targeting of specific biomolecules. The effect of the drug on the secondary structure distribution is monitored label-free in real time and provides thereby direct information about the efficacy of the potential drug.

Abstract: Provided herein is a biosensor for conformation and secondary structure analysis, notably for the direct non-invasive qualitative secondary structure analysis of a single selected protein within a complex mixture, as e.g. a body fluid, by vibrational spectroscopic methods. For the analysis it is not required that the selected substance be isolated, concentrated, or pretreated by a special preparative procedure.