Optimization of the Cyanalyzer by Defining Maximum Sample Volume, Testing Durability of Adhesive, and Evaluating Micro-Solenoids Natalie Boykoffa, Randy Jacksonb and Brian A. Logue*b a New York University b South Dakota State University ABSTRACT EXPERIMENTAL RESULTS Micro-Solenoids Build circuit and write code Design and test prototype for successful reagent delivery and cartridge ejection Durability of Adhesive Duration that the solutions sat did not damage adhesive Pressure expended did not harm durability of adhesive Cyanide, a fast acting, highly toxic chemical that inhibits ATP synthesis.1 Cyanide exposure may occur from a variety of sources. Chemical Warfare Agent (CWA) Essential reagent for industry and research labs2 Gas produced from burning polyurethane and vinyl during house fires3 Ingestion through foods such as almonds, spinach, and peach pits1 Micro-Solenoid Even force, faster speed, less distance traveled compared to linear actuator Reagent delivery comparable to manual delivery (see figure 7) Figure 1: Cyanide ion Figure 6: Stacked solenoids set to depress solution RESULTS The Cyanalyzer (see Figure 2) is a rapid, sensitive device that can test for low concentrations of cyanide from a blood sample. Acidifies blood sample with sulfuric acid Combines NaOH Base + Taurine + NDA to form fluorescent -isoindole product2 Takes fluorescence reading to determine original concentration of cyanide Potential Issues in manufacturing: False positives as a result of overflow Bubbles detaching from adhesive Uneven force used for reagent delivery Maximum Sample Volume Addition of 80-95 µL water had no overflow (see Table 2-5) Excess water between trials led to error Table 2: Water Volume = 80 µL. Trial Distance Bubbles Traveled (mm) Observations 1 5mm Few low bubbles, blood + water didn't mix to well, coagulation 2 6mm Few low bubbles, still some coagulation, acid mixed early 3 8mm Low large bubbles, a little coagulation 4 30mm + overflow Large square bubble grow to cap, some overflow to gas chamber 5 Low bubbles, blood + water mixed well, no overflow 6 10mm + 1-20mm Large square bubbles rose high 7 7mm Large low bubbles, no overflow, very little coagulation 8 Large low bubbles, no overflow, a little coagulation 9 9mm + 1-15mm Large low bubbles, no overflow, one tall bubble ~15mm, little 10 9mm Large low bubbles, a little coagulation, no overflow Figure 8: Solenoid set to eject cartridge Figure 2: The Cyanalyzer Figure 7: Comparison of solenoid reagent delivery to manual reagent delivery. CONCLUSION EXPERIMENTAL There is roughly a 15 µL range of water volume added to the sample chamber before overflow is likely to occur. A disposable cartridge may eliminate error due to excess water remaining in the air flow channel between uses. Adhesive is more than appropriate for a disposable cartridge used for one blood sample. Solenoids provide successful delivery of reagent in comparison to the current linear actuator and delivers similar volume to volume delivered by hand. Table 3: Water Volume = 85 µL. Trial Distance Bubbles Traveled (mm) Observations 1 10mm + 1-15mm no overflow, blood + water were mixed well, no coagulation 2 10mm + 2-15mm no overflow a little coagulation, low large bubbles 3 10mm no overflow, blood + water mixed well, no coagulation, low bubbles 4 9mm no overflow, low large bubbles, very little coagulation 5 9mm + 1-15mm no overflow, a little coagulation, low large bubbles Maximum Sample Volume 200 µL sulfuric acid + 15 µL blood + 80 µL water placed in sample chamber Connected cartridge to air flow from Cyanalyzer and watched for overflow Increased water volume by 5 µL increments until consistent reaction bubbles reached the top of the chamber Table 4: Water Volume = 90 µL. Trial Distance Bubbles Traveled (mm) Observations 1 9mm no overflow, very little coagulation, low large bubbles 2 8mm + 1-20mm no overflow, a little coagulation, low bubbles 3 20mm no overflow but a few bubbles made it to the very top 4 10mm + 3-25mm no overflow, most bubbles remained low but 3 bubbles almost rose to the top 5 10mm + 2-20mm no overflow, no coagulation, only two higher column bubbles REFERENCES Durability of Adhesive Filled 2 sets of 24 bubbles with 8 different solutions (see Table 1) Left one set for a one-week period Depressed and refilled second set 50 times Figure 3: Cartridge with sample chamber (right) and capture chamber (left) Barilllo, D. J., (2009) Diagnosis and Treatment of Cyanide Toxicity. Journal of Burn Care & Research, Vol. 30, p 148-152. DOI: 10.1097/BCR.0b013e3181923b91 Jackson, Randy, et al. “Development of a Fluorescence-Based Sensor for Rapid Diagnosis of Cyanide Exposure.” Analytical Chemistry 2014 86 (3), 1845-1852. DOI: 10.1021/ac403846s Santiago, M., (2013) Pediatric Cyanide Poisoning by Fire Smoke Inhalation: A European Expert Consensus. Pediatric Emergency Care, Vol. 29, Issue 11, p 1234-1240. DOI: 10.1097/PEC.0b013e3182aa4ee1 Table 5: Water Volume = 95 µL. Trial Distance Bubbles Traveled (mm) Observations 1 10mm + 1-15mm no overflow, a little coagulation, all low bubbles except one 15mm column bubble 2 10mm + 1-18mm 3 15mm + 3-30mm no overflow, low bubbles or 15mm column bubbles, and a few 30mm columns 4 15mm + 2-20mm no overflow, 15mm columns and two 20mm column bubbles, mixed well 5 10mm + 2-25mm no overflow, mostly 10mm bubbles with a few reaching 25mm, well mixed Table 1: Solution set up ACKNOLEDGEMENTS # Solution 1 H2O 2 Acid (2M H2SO4) 3 Ethanol 4 Base (0.1M NaOH + water) 5 NDA (0.002M methanol + water) 6 Taurine (0.05M buffer) 7 Methanol 8 Buffer This work was made possible by the National Science Foundation REU Security Printing and Anti-Counterfeiting Site EEC-1559958 Special thanks to Dr. Boysen, Department of Humanities, SDSMT Figure 5: Set of 24 bubbles