1
                                                                     Exhibit 4.7


THIS NOTE HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933 OR APPLICABLE
STATE SECURITIES LAWS AND MAY NOT BE TRANSFERRED OR OTHERWISE DISPOSED OF UNLESS
IT HAS BEEN REGISTERED UNDER SUCH ACT AND LAWS OR AN EXEMPTION FROM REGISTRATION
IS AVAILABLE.


                                BIO-PLEXUS, INC.

                              TERM PROMISSORY NOTE

$250,000.00                                                 Vernon, Connecticut
                                                             September 8, 1998

      FOR VALUE RECEIVED the undersigned, BIO-PLEXUS, INC., a Connecticut
corporation with its principal place of business in Vernon, Connecticut (the
"Maker") hereby promises to pay to the order of CARL R. SAHI, an individual
residing at 398 High Street, Coventry, Connecticut ("Holder") the principal sum
of Two Hundred Fifty Thousand Dollars ($250,000.00), together with interest
thereon at the rate set forth below from the date of this Note. Principal and
interest shall be paid as set forth below. Payment of principal and interest
shall be made in lawful money of the United States of America at the address of
Holder as referenced herein or at such other place as Holder shall have
designated to the Maker in writing.

      This Note shall have the following additional terms and provisions:

      1. Principal Payment. If not sooner paid, the principal amount of this
Note shall be paid on September 8, 1999 (the "Maturity Date").

      2. Interest. Interest on this Note shall be payable quarterly in arrears
commencing on December 8, 1998, and thereafter on March 8, 1999, June 8, 1999,
and the final payment due September 8, 1999, at the place heretofore designated
for the payment of principal, in like money, at the rate of eight percent (8.0%)
per annum. Interest on this Note shall be computed on a 365/365 simple interest
basis, that is, by applying the ratio of the annual interest rate divided by the
number of days in the year times the outstanding principal balance times the
actual number of days the principal balance is outstanding.

      3. Payment; Prepayment. This Note may be prepaid in whole or in part at
any time without prior notice or penalty. Early payments will not relieve Maker
of its obligation to make payments in accordance with the payment schedule,
except upon agreement by Holder, but will be applied to reduce the unpaid
principal balance and may result in reduction or elimination of one or more
scheduled payments.

      4. Events of Default; Acceleration. The following shall constitute "Events
of Default" under this Note:
   2
      (i) A default by the Maker in the payment of any part of the principal
amount or interest of this Note within ten (10) days after the same shall become
due and payable, whether at the Maturity Date or at any other date fixed for
payment.

      (ii) The entry of a decree or order for relief by a court having
jurisdiction in respect of the Maker in an involuntary case under the federal
bankruptcy laws, as now or hereafter constituted, or any other applicable
federal or state bankruptcy, insolvency or other similar law, or the appointment
of a receiver, liquidator, assignee, custodian, trustee, sequestrator (or
similar official) of the Maker or for any substantial part of the Maker's
property, or the issuance of an order for the winding-up or liquidation of the
affairs of the Maker and the continuance of such decree or order unstayed and in
effect for a period of sixty (60) consecutive days; or the commencement by the
Maker of a voluntary case under the federal bankruptcy laws, as now or hereafter
constituted, or any other applicable federal or state bankruptcy, insolvency or
other similar law, or the consent by the Maker to the appointment of, or taking
possession by, a receiver, liquidator, assignee, trustee, custodian,
sequestrator (or other similar official) of the Maker or for any substantial
part of the property of the Maker, or the making by the Maker of an assignment
for the benefit of creditors, or the taking by the Maker of any corporate action
in furtherance of any of the foregoing.

      (iii) The dissolution and winding up of the affairs of the Maker.

      If any of the foregoing Events of Default shall occur, Holder may, at his
option, by written notice to the Maker, accelerate the Maker's obligations
hereunder and declare the entire unpaid principal amount, together with accrued
and unpaid interest thereon, to be immediately due and payable. In addition, in
such event, at Holder's election, the interest rate payable hereunder shall
increase to twelve percent (12%) per annum.

      5. Remedies on Default. In case one or more Events of Default shall occur
and be continuing, and this Note shall be due and payable as set forth in
Section 5 hereof and, subject to the terms hereof, Holder may proceed to protect
and enforce Holder's rights by an action at law, suit in equity or other
appropriate proceeding, whether for the specific performance of any agreement
contained herein, or for an injunction against a violation of any of the terms
hereof, or in aid of the exercise of any power granted hereby or by law. In the
event of default, the Maker agrees to pay to Holder such further amount as shall
be sufficient to cover the reasonable cost and expenses of collection, and all
reasonable costs related to Holder's enforcement of Holder's rights under this
Note, including, without limitation, reasonable attorneys' fees and expenses
whether or not a formal action is commenced. No right, power or remedy conferred
hereby upon Holder shall be exclusive of any other right, power or remedy
referred to herein nor now or hereafter available at law, in equity, by statute
or otherwise. No course of dealing and no delay on the part of Holder in
exercising any right, power or remedy shall operate as a waiver thereof or
otherwise prejudice Holder's rights, powers and remedies.


                                       -2-
   3
      6. Exchange of Note. At the request of Holder and subject to the terms
hereof, upon surrender of this Note to the Maker at its principal office, the
Maker at its expense will issue in exchange hereof a new Note or Notes, in such
denomination or denominations and payable to the order of such payee or payees
as may be requested. Such new Note or Notes shall be in the form of this Note
and shall be in an aggregate principal amount equal to the principal amount of
this Note then outstanding.

      7. Replacement of Note. Upon receipt of evidence reasonably satisfactory
to the Maker of the loss, theft, destruction or mutilation of this Note and, in
the case of any such loss, theft or destruction, upon delivery of an
indemnification agreement by Holder in a form reasonably acceptable to the
Maker, or, in the case of any such mutilation, upon surrender and cancellation
of this Note, the Maker at its expense will execute and deliver, in lieu hereof,
a new Note of like tenor.

      8. Transfer of Note. Transfer of this Note is subject to restrictions
imposed by federal and state securities laws.

      9. Maximum Rate of Interest. Notwithstanding any provisions of this Note,
it is the understanding and agreement of the Maker and Holder that the maximum
rate of interest to be paid by the Maker to Holder shall not exceed the highest
rate of interest permissible to be charged by Holder under applicable law. Any
amount paid in excess of such rate shall be considered to have been a payment in
reduction of principal.

      10. Notices. Any notice, request or instruction to be given hereunder
shall be in writing, shall be hand-delivered, sent by facsimile transmission,
mailed by certified mail, return receipt requested, postage prepaid and
addressed as follows, if to the Maker, at 129 Reservoir Road, Vernon,
Connecticut 06066; and if to Holder, addressed to Holder's address as shown on
the records of the Maker. Either of the addresses specified above may be changed
by notice given as herein provided. All communications will be deemed effective
upon receipt.

      11. General. This Note shall be governed by and construed and enforced in
accordance with the laws of the State of Connecticut without giving effect to
its choice of law provisions. The paragraph headings contained herein are for
reference purposes only and shall not in any way affect the meaning or
interpretation of the terms of this Note. This Note shall be binding upon the
Maker and its successors and assigns and shall inure to the benefit of and be
enforceable by Holder and Holder's successors and assigns. This Note may not be
modified or altered in any manner except by a signed writing. The failure of
Holder at any time or times to require performance of any provision hereof shall
in no manner affect the right at a later time to enforce the same. No waiver by
Holder of any condition of this Note or the breach of any provision hereof,
whether by conduct or otherwise, in any one or more instances shall be deemed to
be construed as a further or continuing waiver of any such condition or breach.
By accepting this Note, Holder agrees to be bound by the terms and conditions
hereof.


                                       -3-
   4
      12. COMMERCIAL TRANSACTION. THE MAKER ACKNOWLEDGES THAT THE DELIVERY OF
THIS NOTE IS PART OF A COMMERCIAL TRANSACTION AND NOT A CONSUMER TRANSACTION AND
WAIVES ANY RIGHT TO A NOTICE AND HEARING UNDER CHAPTER 903a OF THE CONNECTICUT
GENERAL STATUTES, AS AMENDED, OR OTHER STATUTE OR STATUTES AFFECTING PREJUDGMENT
REMEDIES AND AUTHORIZES HOLDER'S ATTORNEY TO ISSUE A WRIT FOR A PREJUDGMENT
REMEDY WITHOUT COURT ORDER, PROVIDED THE COMPLAINT SHALL SET FORTH A COPY OF
THIS WAIVER. FURTHER, TO THE EXTENT ALLOWED UNDER APPLICABLE LAW, MAKER HEREBY
WAIVES DEMAND, PRESENTMENT FOR PAYMENT, PROTEST, NOTICE OF PROTEST, NOTICE OF
DISHONOR, DILIGENCE IN COLLECTION, NOTICE OF NONPAYMENT OF THIS NOTE AND ANY AND
ALL NOTICES OF A LIKE NATURE.


                                       BIO-PLEXUS, INC.



                                       By /s/ Richard L. Higgins
                                          -------------------------------------
                                              Richard L. Higgins
                                              President and CEO


                                       -4-