PORTABLE SINGLE UNIT DEVICE FOR OCHRATOXIN A (OTA) TOXICITY ANALYSIS FOR RICE QUALITY MONITORING

Abstract

A single unit, handheld field portable apparatus and method for analyzing Ochratoxin A (OTA) in rice quality monitoring, based on fluorescence signal output. Aliquots may be analyzed by adding at least one or more reagents to the sample aliquot that reacts selectively with an analyte contained therein. The reaction product, which is selective for the analyte of interest and proportional to its concentration, is measured with an appropriate detector. This enables simple and accurate testing of samples using time honored wet-chemical analysis method in microliter volume regimes while producing remarkably small volumes of waste. The device includes a multipurpose controller board for processing and analysis purpose, a camera which is integrated with the controller, a resistive touch liquid crystal display to view the results, a light emitting diode to emit the UV light, and a power bank. The device may operate using a touch display.

Claims

1. A device comprising: a display interface; a controller board, connected to the display interface, configured for data processing and analysis; a camera which is integrated with the controller; a camera board to support the camera; a sample holder configured to mount a sample; a light emitting diode inserted in a wall of the sample holder and configured so that the sample is in front of the light emitting diode; a reagent holder configured to hold extraction reagents and a nano probe; and a power bank that powers components of the device.

2. The device of claim 1, wherein the display is a resistive touch liquid crystal display.

3. The device of claim 1, wherein the display is attached with the controller board via Display Serial Interface (DSI).

4. The device of claim 1, wherein the controller board is a single board programmable computer (SBC).

5. The device of claim 1, wherein the camera is attached about 2.5 cm to 3 cm above the sample holder and a lens/sensor of the camera board is aligned to the center of the sample holder.

6. The device of claim 4, wherein the camera takes power through Camera Serial Interface (CSI) from the SBC.

7. The device of claim 1, wherein the light emitting diode has excitation wavelength between 350-370 nm to excite the analyte and generate a fluorescence image.

8. The device of claim 1, wherein the samples are excited through UV light.

9. The device of claim 1, wherein the sample holder holds a cuvette of 2.5 mL.

10. The device of claim 1, for use in on-site sample analysis.

11. The device of claim 1, wherein the sample comprises Ochratoxin A (OTA).

12. A method of testing Ochratoxin A (OTA), comprising: a) performing extraction on a sample comprising OTA with a solvent; b) inserting the sample into a sample holder with aid of a sample cuvette; c) adding detection reagent to the sample; d) exciting the sample; e) performing image capturing and processing; and f) displaying results on an interface of a device.

13. The method of claim 12, wherein the solvent is a mixture of acetonitrile-water.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0007] Other features and advantages of the invention will become apparent from the following description of some forms of embodiment of the invention, given as a nonlimiting example, with the help of the appended diagrams illustrated in the attached drawings, in which:

[0008] FIG. 1 represents the actual design of prototype and schematic presentation of the hardware components used in the fabrication of the prototype.

[0009] FIG. 2 is a flow chart illustrating the programming and functions to generate output signal and subsequently the display for users.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

[0010] The device includes a multipurpose controller board (1.1) for processing and analysis purpose, a camera (1.3) which is integrated with the controller, a resistive touch liquid crystal display (1.7) to view the results (008), a Light emitting diode (1.5) (wavelength in the range of 350 nm-500 nm depending on the toxin of interest) to emit the UV light, Micro secure digital (SD) card (1.6) and a portable power bank (1.2). A plastic cuvette (1.4) can be used as a sample holder.

[0011] The device operates (001) using a touch display (1.7) to boot the system (002). The camera (1.3) captures an image in a black box with UV excitation (003) and sends the image (004) to the brain of the device which is controller board (1.1). The image (004) is processed (e.g., in a JPG file). The noise of the image is filtered (005) by using special algorithms (007). Finally, to determine the level of OTA in rice sample, several steps are as follows, i.e. determination of the average pixel value of the image resulted from image segmentation using image processing algorithm (007), conversion of the original image (004), as well as assignment of value. The controller board is programmed in a unique and simple way to extract details (006) of the image (004) using image processing algorithms (007). Based on the programmed algorithm (007), the smart controller (1.1) will analyse the pixel by pixel information of the image (004), which is processed by the controller (1.1), and make a decision on the basis of machine learning algorithms. The process is to determine the center point of identified object to determine the object area. The area is then analyzed to measure the average and deviation standard of pixel values.

EXAMPLE

Experimental Details

[0012] A stock standard solution of 1 mg/ml was prepared by dissolving 5 mg of OTA in 5 ml of methanol and then stored at 20 C. OTA solutions in methanol stored at 20 C. are stable over an extended period of time. Working standard solutions in the concentration level of 0.5-200 ng/mL were prepared by diluting the stock solution. pH was adjusted to 7.4. 2 mL of the working standard solutions were added in the plastic cuvettes (1.4) to perform the testing in the prototype (1.8). The prototype (1.8) generated images and RGB were used to build the library.

[0013] Use of nano probes in the sensing of analytes has been increased tremendously. Nanomaterial based signal amplification have gained much attention with additional benefits for rapid analysis. Cerium oxide nanoparticles were used to amplify the fluorescence based signal of the tested analyte. A stock standard solution of 1 mg/ml was prepared by dissolving 5 mg OTA in 5 ml of methanol and then stored at 20 C. OTA solutions in methanol stored at 20 C. are stable over an extended period of time. Working standard solution at the concentration level of 5 ng/mL was prepared by diluting the stock solution. pH was adjusted to 7.4. 2 mL of the working standard solutions and nanoceria particle at concentration of 50 ng/mL were added in the plastic cuvettes (1.4) to perform the testing in the prototype (1.8). The prototype (1.8) generated images and RGB were used to build the library.

[0014] Acetonitrile was employed as the testing medium. The signal amplification efficiency of two nanoprobes cerium oxide and N-doped titanium oxide nanoparticles was monitored. [0015] a) A stock standard solution of 1 mg/ml was prepared by dissolving 5 mg OTA in 5 ml of methanol and then stored at 20 C. OTA solutions in methanol stored at 20 C. are stable over an extended period of time. Working standard solution at the concentration level of 5 ng/mL was prepared by diluting the stock solution in the solvent acetonitrile-water (6:4, v/v). 2 mL of the working standard solutions in the solvent acetonitrile-water (6:4, v/v), and nanoceria particle at concentration of 50 ng/mL were added in the plastic cuvettes (1.4) to perform the testing in the prototype (1.8). The prototype (1.8) generated images and RGB were used to build the library. [0016] b) A stock standard solution of 1 mg/ml was prepared by dissolving 5 mg OTA in 5 ml of methanol and then stored at 20 C. OTA solutions in methanol stored at 20 C. are stable over an extended period of time. Working standard solution at the concentration level of 5 ng/mL was prepared by diluting the stock solution in the solvent acetonitrile-water (6:4, v/v). 2 mL of the working standard solutions in the solvent acetonitrile-water (6:4, v/v), and N-doped Titanium oxide particle at concentration of 50 ng/mL were added in the plastic cuvettes (1.4) to perform the testing in the prototype (1.8). The prototype (1.8) generated images and RGB were used to build the library.

[0017] Food authorities all over the world have established a permissible limit of 3 g/Kg of OTA in cereal samples. Therefore, OTA at a level of 3 g/Kg was used to build the library. Certified Rice samples were used to construct the library for future field applications. [0018] a) Sample of rice is finely ground using mortar and pestle and was spiked with OTA at concentration of 3 g/kg. The weighed crushed rice (2 g) were extracted in 4 mL of solvent mixture of acetonitrile-water (6:4, v/v) in glass vials. Extraction was carried out for 10 min using manual shaking till the clear solvent changes its color to milky solution. Extract was filtered using whattman filter paper (cat. no. 1001 12.5). 2 mL of the filtrate solution were added in the plastic cuvettes (1.4) to perform the testing in the prototype (1.8). The prototype (1.8) generated images and RGB were used to build the library. [0019] b) Sample of rice was finely ground using mortar and pestle and was spiked with OTA at concentration of 3 g/kg. The weighed crushed rice (2 g) were extracted in 4 mL of solvent mixture of acetonitrile-water (6:4, v/v) in glass vials. Extraction was carried out for 10 min using manual shaking till the clear solvent changes its color to milky solution. Extract was filtered using whattman filter paper (cat. no. 1001 12.5). 2 mL of the filtrate solution and nanoceria particle at concentration of 50 ng/mL were added in the plastic cuvettes (1.4) to perform the testing in the prototype (1.8). The prototype (1.8) generated images and RGB were used to build the library. [0020] c) Sample of rice was finely ground using mortar and pestle and was spiked with OTA at concentration of 3 g/kg. The weighed crushed rice (2 g) were extracted in 4 mL of solvent mixture of acetonitrile-water (6:4, v/v) in glass vials. Extraction was carried out for 10 min using manual shaking till the clear solvent changes its color to milky solution. Extract was filtered using whattman filter paper (cat. no. 1001 12.5). 2 mL of the filtrate solution and N-doped Titanium oxide at concentration of 50 ng/mL were added in the plastic cuvettes (1.4) to perform the testing in the prototype (1.8). The prototype (1.8) generated images and RGB were used to build the library.