Combination optical hemoglobin and electrochemical lead assay
A sensor and analyzer for measuring an analyte in a liquid sample are disclosed. The sensor includes a substrate with a reservoir disposed therein. The reservoir may include a top surface and a bottom surface, at least one transparent portion forming at least a part of the bottom surface of the reservoir, and a reflector disposed on the upper surface of the reservoir at a location opposite the at least one transparent portion. The analyzer may include a support surface, an aperture extending through the support surface, a light source disposed below the support surface and oriented so that at least a portion of the light emitted from the light source passes through the aperture, and a detector configured to measure an intensity of light received at the detector.
1. A sensor for measuring an analyte in a liquid sample, the sensor comprising:
a base layer forming a bottom surface of a reservoir, the reservoir also having a top surface, the base layer including at least one transparent portion forming at least a part of the bottom surface of the reservoir;
a first spacer layer disposed on the base layer, the first spacer layer having a first void extending through a thickness of the first spacer layer;
a second spacer layer disposed on the first spacer layer, the second spacer layer having a second void extending through a thickness of the second spacer layer, at least a portion of a bottom surface of the second spacer layer comprising a first portion of the top surface of the reservoir, wherein the first portion comprises a reflector;
a lid disposed on the second spacer layer, the lid having a bottom surface, wherein at least a portion of the bottom surface of the lid forms at least a second portion of the top surface of the reservoir; and
wherein the reservoir comprises a first depth, between the bottom surface of the reservoir and the first portion of the top surface of the reservoir, and a second depth, between the bottom surface of the reservoir and the second portion of the top surface of the reservoir, wherein the first depth is less than the second depth, and wherein the reflector is disposed on the first portion of the top surface of the reservoir.
2. The sensor of claim 1 , wherein the second spacer layer also comprises a third void extending through the thickness of the second spacer layer, the second and third voids separated on the second spacer layer by a bridge, a bottom surface of the bridge comprising the portion of the bottom surface of the second spacer layer that comprises the portion of the top surface of the reservoir comprising the reflector.
3. The sensor of claim 1 , wherein the first depth is equal to the thickness of the first spacer layer, and the second depth is equal to a combined thickness of the thickness of the first spacer layer and the thickness of the second spacer layer.
4. The sensor of claim 1 , further comprising at least one electrode disposed on a bottom surface of the reservoir and at least one electrical contact disposed on the base layer, and wherein the at least one electrode is in electrical communication with the at least one electrical contact.
5. The sensor of claim 1 , further comprising at least one electrode disposed on a bottom surface of the reservoir at a location where the reservoir comprises the second depth and at least one electrical contact disposed on the base layer, wherein the at least one electrode is in electrical communication with the at least one electrical contact.
6. The sensor of claim 5 , wherein a first of the at least one electrodes comprises a colloidal gold deposit.
7. The sensor of claim 6 , wherein the sensor is configured to be used to analyze for a hemoglobin concentration of the liquid sample using an optical measurement.