Ex Parte Cao

Patent Trial and Appeal Board

Mar 4, 2016

12376371 (P.T.A.B. Mar. 4, 2016)

UNITED STA TES p A TENT AND TRADEMARK OFFICE
APPLICATION NO. FILING DATE
12/376,371 0512612009
23557 7590 03/08/2016
SALIW ANCHIK, LLOYD & EISENSCHENK
A PROFESSIONAL ASSOCIATION
PO Box 142950
GAINESVILLE, FL 32614
FIRST NAMED INVENTOR
Y. Charles Cao
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www .uspto.gov
ATTORNEY DOCKET NO. CONFIRMATION NO.
UF.519XC1 6024
EXAMINER
BRATLAND JR, KENNETH A
ART UNIT PAPER NUMBER
1714
NOTIFICATION DATE DELIVERY MODE
03/08/2016 ELECTRONIC
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address( es):
euspto@slepatents.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte Y. CHARLES CAO
Appeal2014-007575
Application 12/3 7 6,3 71
Technology Center 1700
Before JEFFREY T. SMITH, ELIZABETH M. ROESEL, and
CHRISTOPHER C. KENNEDY, Administrative Patent Judges.
ROESEL, Administrative Patent Judge.
DECISION ON APPEAL
Appellant1 appeals under 35 U.S.C. § 134(a) from the Examiner's
decision rejecting claims 1-8, 11, and 21-26 under 35 U.S.C. § 103(a). We
have jurisdiction under 35 U.S.C. § 6(b ).
We REVERSE.
1 Appellant identifies the University of Florida Research Foundation, Inc. as
the real party in interest. Br. 1.
Appeal2014-007575
Application 12/3 7 6,3 71
STATEMENT OF THE CASE
Claimed Invention
Appellant claims a method for doping nanocrystals. Br. 14 (claim 1 ).
Claim 1 is the sole independent claim and is reproduced below from
Appellant's Claims Appendix:
1. A method for doping nanocrystals, comprising the
steps of:
synthesizing a starting host particle having a first radius;
incorporating impurity atoms onto a surface of the
starting host particle in the presence of doping precursors to
form a doped starting host particle;
purifying the doped starting host particle by removing
unreacted dopants from the doped starting host particle to form
a purified doped starting host particle; and
growing a host shell around the purified doped starting
host particle to form a doped nanocrystal having a second
radius,
wherein the impurity atoms are radial-positioned at the
first radius.
Br. 14.
Bawendi et al.
("Bawendi)
Guyot-Sionnest et al.
("Guyot")
Jun et al.
("Jun")
References
US 6,322,901 Bl Nov. 27, 2001
US 2005/0189534 Al Sept. 1, 2005
US 7,621,997 B2 Nov. 24, 2009
Steven C. Erwin, et al., Doping of Semiconductor Nanocrystals, 436 Nature
Letters 91-94 (July 7, 2005) ("Erwin")
2
Appeal2014-007575
Application 12/3 7 6,3 71
The Rejections
1. Claims 1-8, 11, 21-22, and 25 are rejected under 35 U.S.C.
§ 103(a) as unpatentable over Erwin in view of Guyot. Final Action 2-12.2
2. Claims 23 and 24 are rejected under 35 U.S.C. § 103(a) as
unpatentable over Erwin in view of Guyot and further in view of Jun. Id. at
12-14.
3. Claim 26 is rejected under 35 U.S.C. § 103(a) as unpatentable over
Erwin in view of Guyot and further in view ofBawendi. Id. at 14--15.
ANALYSIS
The Examiner finds that Erwin discloses a method for doping
nanocrystals embodying the limitations of claim 1, except for the third step
("purifying the doped starting host particle ... "). Final Action 2-3 (citing
Erwin Abstract, Fig. 4a, and "Experimental" section). The Examiner finds
that Guyot teaches the formation of doped nanocrystals, including a
purification step. Id. at 3 (citing Guyot i-fi-132-34, 41, 55-58). The
Examiner quotes Guyot's disclosure that "[u]pon cooling to ambient
temperature, the reaction mixture is purified and size-selectively precipitated
... resulting in CdSe nanocrystals of nearly monodisperse size." Id. at 17
(quoting Guyot i156). The Examiner concludes that, in view of this teaching
of Guyot, it would have been obvious to purify doped starting host particles
formed according to the method of Erwin before forming a shell layer in
order to ensure that the starting host particles are of nearly monodisperse
size and to form a highly undoped shell layer. Id. at 3--4, 17.
2 Final Action dated June 26, 2013.
3
Appeal2014-007575
Application 12/3 7 6,3 71
Appellant argues that the combination of Erwin and Guyot fails to
teach "purifying the doped starting host particle by removing unreacted
dopants from the doped starting host particle to form a purified doped
starting host particle," as recited in the third step of claim 1. Br. 6-7.
Appellant acknowledges that Guyot discloses a method for forming core-
shell nanoparticles, including a purification step. Citing a declaration of the
inventor,3 however, Appellant argues that Guyot's purification step is carried
out only after formation of the shell, not on the intermediate core. Br. 6.
Dr. Cao directs us to specific teachings in Guyot paragraphs 56 and 58 and
avers that Guyot teaches purification of a completed core/shell, not an
intermediate product purification. Cao Deel. 4--5.
We interpret Appellant's claim 1 as requiring that the "purifying" step
be performed after the "incorporating" step and before the shell-growing
step. See Baldwin Graphic Sys., Inc. v. Siebert, Inc., 512 F.3d 1338, 1345
(Fed. Cir. 2008) ("as a general rule the claim is not limited to performance
of the steps in the order recited, unless the claim explicitly or implicitly
requires a specific order"). Here, a plain reading of claim 1 evinces that the
"incorporating," "purifying," and "growing" steps must be performed in the
order they are recited. By its express terms, the "purifying" step is
performed on "the doped starting host particle," which is the product of the
preceding "incorporating" step. Similarly, the "growing" step is performed
on "the purified doped starting host particle," which is the product of the
preceding "purifying" step. Accordingly, the "purifying" step is correctly
3 Declaration ofY. Charles Cao, Ph.D., under 37 C.F.R. § 1.132, filed
Aug. 29, 2013 ("Cao Declaration" or "Cao Deel.").
4
Appeal2014-007575
Application 12/3 7 6,3 71
interpreted as an intermediate step, which is performed after formation of a
doped starting host particle, i.e., a doped core, and before formation of a
shell.
The Cao Declaration, pages 4-5, persuades us that the Examiner errs
in relying on Guyot paragraphs 55-58 as teaching or suggesting that an
intermediate purification step be performed after forming a core and before
forming a shell of a core-shell nanoparticle. Guyot paragraphs 55 and 56
disclose a method for forming CdSe nanocrystals, and Guyot paragraphs 57
and 58 disclose a method for forming CdSe/ZnS core-shell nanocrystals,
starting with the CdSe core prepared according to paragraph 56. As
explained by Dr. Cao, however, Guyot's description of the purification and
shell-forming steps demonstrate that the purification step is performed only
on a final nanocrystal product, not on an intermediate core before the
formation of a shell. Cao Deel. 4-5 (quoting Guyot i-fi-156, 58).
The Examiner finds that Guyot "is merely referenced to teach that the
use of purification processes is known in the art and may be performed after
formation of the nanocrystal core." Ans. 19 (citing Guyot i157). The
Examiner further finds that "purification is beneficial as it promotes the
formation of nanocrystals of nearly monodisperse sizes," and that in seeking
to produce uniformly sized nanocrystals having a doped core and undoped
shell, "an ordinary artisan would be motivated to purify the solution before
forming the shell layer." Id. (citing Erwin Fig. 4(a)).
As noted above, Appellant and Dr. Cao persuade us that Guyot
teaches purifying a final nanocrystal product, but does not teach purifying an
intermediate core before forming a shell. In fact, Guyot teaches to perform a
purification step only after formation of completed nanoparticles and to skip
5
Appeal2014-007575
Application 12/3 7 6,3 71
any purification of the nanocrystals, if they are to be used to form the core of
core-shell nanoparticles. Guyot i-fi-155-58; Cao Deel. 4--5. Accordingly, the
Examiner errs in finding that Guyot teaches that purification "may be
performed after formation of the nanocrystal core." Ans. 19. Furthermore,
Guyot's teaching regarding "nanocrystals of nearly monodisperse sizes,"
Guyot i156, pertains to a final product, not an intermediate core.
Accordingly, the Examiner errs in relying upon this teaching of Guyot to
show a motivation to modify Erwin's disclosed method to include an
intermediate purification step.
Based on the current record, we are persuaded that the combined
teachings of Erwin and Guyot are insufficient to support the Examiner's
proposed modification of Erwin's disclosed method of forming core-shell
nanoparticles to include an intermediate purification step after the forming
the doped core and before forming the undoped shell, as recited in claim 1.
The foregoing deficiencies in the Examiner; s findings and conclusions
regarding the combination of Erwin and Guyot are not remedied by the
Examiner's findings regarding Jun or Bawendi, cited in support of the
second and third grounds of rejection, respectively. For all of the foregoing
reasons, we do not sustain the rejection of claims 1-8, 11, and 21-26 under
35 U.S.C. § 103(a) as unpatentable over Erwin, Guyot, Jun, and Bawendi.
CONCLUSION OF LAW AND DECISION
The decision of the Examiner is reversed.
REVERSED
6