Methods and systems for analysis

Abstract

Provided herein are systems and methods for the detection, quantification, and/or monitoring of analytes in samples. The systems and methods can be used, for example, to track the deposition and electrochemical behavior of individual nanoparticles and nanoparticles clusters clusters in situ with high spatial and temporal resolution. The systems and methods can be used to track the deposition and oxidation of several hundreds to thousands of nanoparticles simultaneously and reconstruct their voltammetric curves at the single nanoparticle level.

What is claimed is: 
     
         1 . A system, comprising:
 a) an electrochemical cell comprising
 i) a working electrode in electrochemical contact with a liquid sample comprising an analyte; 
 ii) a sample containment vessel comprising a top end, a bottom end, an exterior surface, and an interior void defined by an interior surface;
 wherein the bottom end forms a liquid tight seal with the working electrode; 
 wherein the liquid sample is contained in the volume defined by the interior void of the sample containment vessel and the working electrode; 
 
 iii) one or more additional electrodes in electrochemical contact with the liquid sample; and 
 iv) a power supply electrically coupled to the working electrode and the one or more additional electrodes; 
   b) a light source configured to illuminate the liquid sample; and   c) an instrument configured to capture an optical signal from the liquid sample.   
     
     
         2 . The system of  claim 1 , wherein the sample containment vessel further comprises a channel that punctuates the interior surface and leads through the sample containment vessel to the top end or exterior surface of the sample containment vessel,
 wherein the one or more additional electrodes can be inserted through the channel such that the one or more additional electrodes are in electrochemical contact with the liquid sample; and   wherein the one or more additional electrodes form a liquid tight seal with the channel.   
     
     
         3 . The system of  claim 1 , wherein the sample containment vessel further comprises a supporting member comprising a top end, a bottom end, an exterior surface, and an interior void defined by an interior surface, wherein the top end forms a liquid tight seal with the working electrode. 
     
     
         4 . The system of  claim 1 , further comprising a first lens. 
     
     
         5 . The system of  claim 4 , wherein the system is configured such that the light source and the instrument are below the first lens, and the electrochemical cell is above the first lens. 
     
     
         6 . The system of  claim 5 , where in the first lens is a microscope objective. 
     
     
         7 . The system of  claim 4 , further comprising a second lens. 
     
     
         8 . The system of  claim 7 , wherein the system is aligned such that:
 the first lens is above the instrument;   the electrochemical cell is above the first lens;   the second lens is above the electrochemical cell; and   the light source is above the second lens.   
     
     
         9 . The system of  claim 8 , wherein the first lens is a dark field microscope objective and the second lens is a dark field microscope condenser. 
     
     
         10 . The system of  claim 1 , further comprising a computing device comprising a processor and a memory operably coupled to the processor, the memory having further computer-executable instructions stored thereon that, when executed by the processor, cause the processor to:
 receive an electrochemical signal from the power supply;   receive an optical signal from the instrument;   process the electrochemical signal to obtain an electrochemical parameter;   process the optical signal to obtain an optical parameter;   optionally correlate the electrochemical parameter to the optical parameter to obtain an optoelectrochemical parameter; and   output the electrochemical parameter, the optical parameter, the optoelectrochemical parameter, or combinations thereof.   
     
     
         11 . The system of  claim 1 , wherein the working electrode is substantially optically transparent. 
     
     
         12 . The system of  claim 1 , wherein the working electrode comprises an indium tin oxide (ITO) coated coverslip. 
     
     
         13 . A method, comprising:
 a) providing an electrochemical cell comprising
 i) a working electrode in electrochemical contact with a liquid sample comprising an analyte; 
 ii) a sample containment vessel comprising a top end, a bottom end, an exterior surface, and an interior void defined by an interior surface;
 wherein the bottom end forms a liquid tight seal with the working electrode; 
 wherein the liquid sample is contained in the volume defined by the interior void of the sample containment vessel and the working electrode; 
 
 iii) one or more additional electrodes in electrochemical contact with the liquid sample; and 
 iv) a power supply electrically coupled to the working electrode and the one or more additional electrodes; 
   b) capturing an electrochemical signal from the liquid sample;   c) capturing an optical signal from the liquid sample;   d) processing the electrochemical signal to obtain an electrochemical parameter;   e) processing the optical signal to obtain an optical parameter;   f) optionally, correlating the optical parameter to the electrochemical parameter to obtain an optoelectrochemical parameter.   
     
     
         14 . The method of  claim 13 , wherein the sample containment device further comprises a supporting member comprising a top end, a bottom end, an exterior surface, and an interior void defined by an interior surface, wherein the top end forms a liquid tight seal with the working electrode. 
     
     
         15 . The method of  claim 13 , wherein the optical signal comprises dark field scattering, electrogenerated chemiluminescence, fluorescence or a combination thereof. 
     
     
         16 . The method of  claim 13 , wherein the optical parameter comprises nanoparticle size. 
     
     
         17 . The method of  claim 13 , wherein the optoelectrochemical parameter comprises the potential at which individual nanoparticles, clusters of nanoparticles, or a combination thereof, of a specific size are formed. 
     
     
         18 . A sample containment vessel, comprising a top end, a bottom end, an exterior surface, and an interior void defined by an interior surface
 wherein the sample containment vessel is configured to receive a working electrode;   wherein the bottom end forms a liquid tight seal with the working electrode;   wherein the volume defined by the interior void of the sample containment vessel and the working electrode is configured to contain a liquid sample; and   wherein the working electrode can be in electrochemical contact with the liquid sample.   
     
     
         19 . The sample containment vessel of  claim 18 , further comprising a channel that punctuates the interior surface of the sample containment vessel and leads through the sample containment vessel to the top end or exterior surface of the sample containment vessel,
 wherein the channel is configured to receive one or more additional electrodes such that the one or more additional electrodes are in electrochemical contact with the liquid sample; and   wherein the one or more additional electrodes form a liquid tight seal with the channel.   
     
     
         20 . The sample containment vessel of  claim 18 , further comprising a supporting member comprising a top end, a bottom end, an exterior surface, and an interior void defined by an interior surface, wherein the top end forms a liquid tight seal with the working electrode.