Albumin-based non-covalent complexes and methods of use thereof

1. A method for determining the presence or absence of a microorganism in a sample, the method comprising:

i) contacting the sample with an aqueous solution comprising a plurality of non-covalent complexes, each non-covalent complex comprising a hydrophobic molecule and a single albumin protein, wherein the hydrophobic molecule is detectable and functionally associates with a microorganism when present in the sample;

ii) detecting one or more properties of the hydrophobic molecule; and

iii) determining that the microorganism is present or absent in the sample based on the detecting.

2. The method of claim 1 , wherein the hydrophobic molecule has one or more intermolecular distance-dependent properties, wherein the detecting comprises measuring in the sample one or more profiles of the one or more intermolecular distance-dependent properties, and wherein the determining comprises determining that the microorganism is present when the one or more profiles indicates the presence of aggregates of the hydrophobic molecule in the sample, or determining that the microorganism is absent when the one or more profiles indicates the absence of aggregates of the hydrophobic molecule in the sample.

3. The method of claim 1 , wherein the microorganism is a pathogenic microorganism.

4. The method of claim 2 , wherein the one or more intermolecular distance-dependent properties are one or more optical properties.

5. The method of claim 4 , wherein the one or more intermolecular distance-dependent properties comprise an optical absorption band and/or a Raman band.

6. The method of claim 4 , wherein the one or more intermolecular distance-dependent properties comprise Förster resonance energy.

7. The method of claim 1 , wherein the hydrophobic molecule is a carotenoid.

8. The method of claim 7 , wherein the carotenoid is a carotene.

9. The method of claim 8 , wherein the carotene is lycopene or β-carotene.

10. The method of claim 2 , wherein the one or more profiles comprises

a) a temporal profile at a fixed spatial point, and/or

b) a spatial profile at a fixed time point, of the height of Raman scattered light for the sample obtained by analyzing the sample with a spectrometer, and

wherein the determining comprises determining the presence or absence the microorganism in the sample based on the height of one of a plurality of characteristic Ramen peaks in the spatial profile, and/or the rate of change of one of the plurality of characteristic Raman peaks in the temporal profile, relative to a corresponding set of reference profiles.

11. The method of claim 1 , wherein the albumin protein is a human serum albumin protein.

12. The method of claim 1 , wherein detecting one or more properties of the hydrophobic molecule comprises

illuminating the sample with a broadband light source; and

collecting and analyzing with a spectrometer light transmitted through the sample, wherein a temporal profile at a fixed spatial point, or a spatial profile at a fixed time point, of the height of Raman and/or a UV-Vis absorption peak is analyzed, wherein

the height of one of a plurality of characteristic Raman and/or UV-vis peaks is used as an indicator when compared with a set of control values, or

the rate of change of one of the plurality of characteristic Raman peaks is used as an indicator, of the presence of the detectable hydrophobic molecule bound to the microorganism in the sample.

13. The method of claim 12 , wherein the microorganism is a pathogenic microorganism.

14. The method of claim 12 , wherein the hydrophobic molecule is a carotene.

15. The method of claim 14 , wherein the carotene is lycopene or β-carotene.

16. The method of any one of claim 12 , wherein the albumin protein is a human serum albumin protein.