ACS New York Section

Analytical Topical Discussion Group

2008 Annual Report

Officers for 2008

Robert P. Nolan, PhD
International Environmental Research Foundation
Post Office Box 3459
Grand Central Station
New York, NY 10063-3459
Tel/Fax (800) 709-0028  E-mail:

Chairman Emeritus        
William E.L. Grossman
Department of Chemistry
Hunter College of The City University of New York
695 Park Avenue
New York, NY   10021
Tel    (212) 772-5338/5330

Thomas Kubic, Director and Program Chair
John Jay School of Criminal Justice of The City University of NY   
899 Tenth Avenue
New York, NY 10019  

David C. Locke, Chairman
Department of Chemistry
Queens College of The City University of New York
65-30 Kissena Boulevard
Flushing, NY   11367-1597
Tel    (718) 997-3271
Urs Jans, Director
Department of Chemistry
The City College of The City University of New York
Convent Avenue & 138th Street
New York, NY   10031
Tel    (212) 650-8369/6052  E-mail:

Emmanuel Chang, Director
Department of Chemistry
York College of The City University of New York
Jamaica, New York 11451  E-mail:

     The Analytical Topical Group held 3 programs in 2008 and continues to benefit from improve attendance (consistently 20 or more) and interest since the partnership was formed with John Jay School of Criminal Justice. The students in the graduate program in analytical chemistry at The City University of New York are required to attend the seminars and the forensic science students from John Jay can get seminar credit for attending. We continue to have little interest from the analytical chemist outside of academia. A problem we are trying to address. We do have interest from the scientific instrument companies to introduce there new technology to the topical group. We find these lectures interesting and do attract outside attendance.

     This year Dr. Emmanuel Chang from York College has joined our Board of Directors. He will be inviting several speakers for the spring 2010 program. He graduated from Rockefeller University and can help in arranging lectures by local analytical chemists and visitors.

Wednesday – April 30, 2008, at 6 PM
The Graduate Center of the City University of New York
365 Fifth Avenue
New York, NY
Science Center Room 4102

In-situ Fabrication of Conducting Polymer Nanocomposites for Biosensing Applications:
Multiple Roles of DNA Functionalized Carbon Nanotubes

Dr. Huixin He
Chemistry Department,
Rutgers University, Newark, NJ 07102

     Conducting polymers are attractive for sensor applications because their electronic and electrochemical properties are highly sensitive to molecular interactions, which provide excellent signal transduction for molecular detection. Among conducting polymers, polyaniline is unique since it is environmentally stable and easy to fabricate. It has been applied widely in chemical sensors but not as much in biosensors. The reason is that native polyaniline is neither electrochemically active nor conductive in neutral solutions, which is a prerequisite for biosensor applications. It is also limited both in the variety of molecules that can be detected and in the selectivity of the detection. Major breakthroughs in this field were the discoveries of self-doped polyaniline and polyelectrolyte-anion-doped polyaniline, which brought polyaniline into the biosensor field due to the improved redox activity and conductivity in neutral pH solutions. However, compared to the parent polyaniline, the electrochemical activity, conductivity, and the chemical and mechanical stabilities of both self-doped polyaniline and bulky polyelectrolyte-doped polyaniline are greatly reduced due to steric effects.

     Here we report that the stability of a self-doped polyaniline, poly(anilineboronic acid) in this work, is greatly improved when it is polymerized in-situ with ss-DNA-wrapped single walled carbon nanotubes (ss-DNA/SWNTs). The conductivity and redox properties of the polyaniline backbone are conserved in neutral solutions (pH = 7.4), and the sensitivity for biomolecular detection is significantly enhanced. We found that the ss-DNA/SWNTs performed multiple roles in the greatly improved properties of the self-doped polyaniline both during and after the polymerization, which makes this work unique compared to previously reported conducting polymer/carbon nanotube composites. First, the ssDNA/SWNTs acted as effective catalytic molecular templates during polymerization of self-doped polyanline so that not only was the polymerization speed increased, but also the quality of the polymer was greatly improved. Second, they functioned as novel active stabilizers after the polymerization, which significantly enhanced the stability of the film. Furthermore, the ss-DNA/SWNTs also acted as conductive polyanionic doping agents and conductive bridges in the resulting polyaniline film, which showed enhanced conductivity and redox activity. Finally, the large surface area of carbon nanotubes greatly increased the density of the functional groups available for sensitive detection of the target analyte.

     Using this material, we developed a non-oxidative approach to electrochemically detect neurotransmitter dopamine with extremely high sensitivity. More importantly, since direct oxidation of dopamine on the electrode was not involved in this sensing approach, its related problems were thus avoided. The high sensitivity along with the improved selectivity of this sensing approach may hold great promise for molecular diagnosis of Parkinson's disease. Changing the functional groups along the polyaniline backbone, we developed extremely sensitive approach for detection of trace level neural toxins, which has been used as chemical warfare agents.

     Biosketch: Dr. Huixin He received her PhD in Peking University, China in 1997. She joined National University of Singapore as a research associate, working mainly on plastic microfluid channels and micropatterns by soft lithography. In 1999, she came to the United States working with Professor Nongjian Tao, first in Florida International University and then Arizona State University. At this period time, she was mainly working on molecular electronics, including the electronic properties of metallic quantum wires and single chain conducting polymer wires. In 2002, she joined chemistry department, Rutgers University at Newark, as an assistant professor. Her current research interests include conducting polymer nanocomposite, especially in the fundamental study of interaction at interfaces in the composite and exploration of the composite materials for chemical and biosensor applications. She is also actively working on developing nonviral gene delivery system using these nanocomposites and other nanomaterials.

Wednesday – March 19, 2007, at 6 PM

The Graduate Center of the City University of New York
 365 Fifth Avenue
New York NY

Statistical Discrimination of Gasoline Samples from Casework using GC-MS
Efforts to Meet the Daubert Challenge

Dr. Nicholas D. K. Petraco
John Jay College of Criminal Justice

     The intention of this study was to differentiate casework liquid gasoline samples by utilizing multivariate pattern recognition procedures on data from gas chromatography-mass spectrometry. A supervised learning approach was undertaken to achieve this goal employing the methods of principal component analysis, canonical variate analysis, orthogonal canonical variate analysis and linear discriminant analysis.The study revealed that the variability in the sample population was sufficient to distinguish all the samples from one another knowing their groups a priori. Canonical variate analysis was able to differentiate all samples in the population using only three dimensions while orthogonal canonical variate analysis required four dimensions. Principal component analysis required ten dimensions of data in order to predict the correct groupings. These results were all cross-validated using the "hold-one-out" method to confirm the classification functions and compute estimates of error rates. These results  have helped to develop procedures to use multivariate analysis applicable to fire debris casework.

     Biosketch: Nicholas D. K. Petraco earned a bachelor’s degree in chemistry from Colgate University in 1998 and a doctorate in quantum chemistry from the University of Georgia in 2002. He was a postdoctoral fellow in applied mathematics at the University of Waterloo from 2002-2004 where after he was appointed to an assistant professorship in chemistry at John Jay College of Criminal Justice and The Graduate Center, City University of New York. His current research interests are in the application of statistical pattern recognition methods to trace evidence. He is also interested in the general application of mathematics and computers to physical evidence analysis problems in forensic science.

Wednesday – December 17, 2008, at 6 PM

The Graduate Center of the City University of New York
 365 Fifth Avenue, New York NY
Science Center Room 4102

Scientific Firearm and Tool Mark Examination.

Peter Diaczuk
Director of Forensic Science Training,
Center for Modern Forensic Practice
John Jay College of Criminal Justice, CUNY.